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Deefstes
August 25th, 2008, 08:07 AM
I'd like to get your thoughts and advice on air sharing during ascent. Let me start by explaining where I'm coming from.

This weekend my wife and I decided to do some skills practicing at the local quarry. We wanted to look at some basic trim issues etc. but also to do air sharing while doing a free ascent with a 3 minute safety stop at 5m.

What a disaster! We started our free ascent at 15m and as soon as my wife took my octo, she became a cork. I'm sure it has nothing to do with using my octo but just that she forgot to mind her buoyancy. I grabbed her by the fin and pulled her down and at the same time dumped all the air from my BC. We must have been at around 10m by the time our upwards movement stopped and I'm surprised that our computers didn't complain of ascent rate violations so it couldn't have been too bad. By now she's realised what happened and she dumped all her air as well and before we knew it, we were back to 15m.

After some heavy finning and air additions to the BC's our buoyancy was sorted. OK, so we started the intended ascent. Things seemed fine although I think it could have been better. We didn't really ascend steadily but rather bobbed up and down with a net upwards movement, probably not ideal but not catastrophic either. The same thing continued through the safety stop and our 3 minute stop constantly varied between 4m and 6m.

If this was a real life emergency I think we'd have survived, even without harm. However, in a real life emergency at least one diver will probably have been much more panicked and things could have been much worse so I think we'll go back and practice this again until we get it right.

Now, your help and advice please.

1. Throughout the exercise, we were in the vertical position. Sorting out our bad buoyancy would probably have been easier if were horizontal but in a real life emergency I'm pretty sure at least one diver will not remain horizontal. Your thoughts? What is a good position for an air sharing ascent?

2. Keeping on the topic of body position, I found that donating an octo made things pretty tricky. We had planned on grabbing each other's BC's with the one hand, facing each other but the awkward looping of the octo hose made that, well, awkward. So we ended up being almost side by side, her to my left. Again, what is the correct way?

3. Both of us kept a close eye on our computers throughout, mostly to keep a tab on our depth. We both had the same computer but even so, they didn't give he exact same readings all the time. So while she thought we we're at 5.4m, I thought we were at 4.6m (this is probably because of the 20sec sample interval). The thing is I'd be trying to get us deeper while she'd be trying to get us shallower or vice versa. Would it perhaps be a better idea for both of us to keep an eye on just one of the computers?

4. Would it not perhaps be a good idea for only one of the two divers (the one who is not OOA, ie. the donating diver) to manage the entire ascent? In other words, the receiving diver has only two tasks, keep the donated octo in your mouth and hold on to the donating diver's BC. The donating diver then makes sure the collective buoyancy is correct and manages the safety stop, monitors the computer etc.

What else can you gurus tell me? I think this might be a valuable skill to master and once we have this one down pat we'll move on to buddy breathing during free ascent with a safety stop.

El Orans
August 25th, 2008, 08:11 AM
I prefer to do my free ascents with an SMB. Having a reference makes it easier to maintain your depth allowing you to focus on the sharing of air.

spectrum
August 25th, 2008, 08:22 AM
#1 Unless the buddy team has practiced horizontal you are probably correct.

#2 This is why I have my alternate second stage on my left. It presents properly to a donor that is face to face or swimming to my left.

#3 The sample rate refers to the data that is logged for download. The display is real time.

#4 Just like while diving somone needs to be driving. Let the "victim" be the follower, that is probably the more stressed diver. The donor will also be the one with ready access to inflator air if too much gets dumped.

Congratulations on making time to practice this sort of stuff.

Pete

battles2a5
August 25th, 2008, 08:25 AM
There are a few things happening in this scenario (both in practice and in "real life"):

1. Recreational configs are not set up very well for air-sharing or air-sharing ascents. They are designed to get you air and get you up to the surface. It is difficult to share air horizontally with rec-length hoses. When you go vertical to share, your bouyancy is going to change a bit and that doesn't help things.
2. IIRC, your wife is a new diver. First on all, good for you for continuing to practice skills and OOA after your training. Second, it is natural for newer divers to increase their breathing and to breathe higher into their lungs during drills. So this is going to increase your bouyancy. This just takes some time to get comfortable with taking the reg out, being conscious of your breathing, and just being comfortable in general.
3. Once you realized you were ascending, you probably over-compensated with your responce to dump air, hence the bobbing up and down. It also sounds like you began the ascent right away after you started sharing air. I would suggest breaking the drill down into part. For instance, donate the reg then stop. Wait a few seconds and make sure your breathing and bouyancy are ok. "OK" eachother then begin the controlled ascent. That may help.
4. The one donating the reg should be controlling the ascent. If the receiving diver is OOA, they don't have any air to inflate the BC. They should be venting on thier own during the ascent but you should be prepared to help them, especially in a face-to-face vertical ascent.
5. Not sure where you are practicing this, but "free" ascents without a visual reference and difficult for everyone, not just new divers. Maintaining depth and a controlled ascent rate is a challenge and requires a LOT of practice to master. This is compounded by the OOA drill. You want to do this on an upline or a wall, or somewhere else where you can maintain a visual reference.

Hope this helps! Keep up the good work with the drills.

danvolker
August 25th, 2008, 08:33 AM
I'd like to get your thoughts and advice on air sharing during ascent. Let me start by explaining where I'm coming from.

This weekend my wife and I decided to do some skills practicing at the local quarry. We wanted to look at some basic trim issues etc. but also to do air sharing while doing a free ascent with a 3 minute safety stop at 5m.

What a disaster! We started our free ascent at 15m and as soon as my wife took my octo, she became a cork. I'm sure it has nothing to do with using my octo but just that she forgot to mind her buoyancy. I grabbed her by the fin and pulled her down and at the same time dumped all the air from my BC. We must have been at around 10m by the time our upwards movement stopped and I'm surprised that our computers didn't complain of ascent rate violations so it couldn't have been too bad. By now she's realised what happened and she dumped all her air as well and before we knew it, we were back to 15m.

After some heavy finning and air additions to the BC's our buoyancy was sorted. OK, so we started the intended ascent. Things seemed fine although I think it could have been better. We didn't really ascend steadily but rather bobbed up and down with a net upwards movement, probably not ideal but not catastrophic either. The same thing continued through the safety stop and our 3 minute stop constantly varied between 4m and 6m.

If this was a real life emergency I think we'd have survived, even without harm. However, in a real life emergency at least one diver will probably have been much more panicked and things could have been much worse so I think we'll go back and practice this again until we get it right.

Now, your help and advice please.

1. Throughout the exercise, we were in the vertical position. Sorting out our bad buoyancy would probably have been easier if were horizontal but in a real life emergency I'm pretty sure at least one diver will not remain horizontal. Your thoughts? What is a good position for an air sharing ascent?

2. Keeping on the topic of body position, I found that donating an octo made things pretty tricky. We had planned on grabbing each other's BC's with the one hand, facing each other but the awkward looping of the octo hose made that, well, awkward. So we ended up being almost side by side, her to my left. Again, what is the correct way?

3. Both of us kept a close eye on our computers throughout, mostly to keep a tab on our depth. We both had the same computer but even so, they didn't give he exact same readings all the time. So while she thought we we're at 5.4m, I thought we were at 4.6m (this is probably because of the 20sec sample interval). The thing is I'd be trying to get us deeper while she'd be trying to get us shallower or vice versa. Would it perhaps be a better idea for both of us to keep an eye on just one of the computers?

4. Would it not perhaps be a good idea for only one of the two divers (the one who is not OOA, ie. the donating diver) to manage the entire ascent? In other words, the receiving diver has only two tasks, keep the donated octo in your mouth and hold on to the donating diver's BC. The donating diver then makes sure the collective buoyancy is correct and manages the safety stop, monitors the computer etc.

What else can you gurus tell me? I think this might be a valuable skill to master and once we have this one down pat we'll move on to buddy breathing during free ascent with a safety stop.


This is one of the foundational points to why you should consider DIR for recreational diving. If you and your wife were each breathing through a long hose primary, with the necklace reg back up, the drill would have played more like this :

On ascent start at 15m , you pass your long hose primary to your wife, with you switching switching instantly to your necklace reg.
You are now swimming comfortably side by side, not bumping into each other, or even slightly hampered--it is exactly like being on your own air supply, and swimming in a buddy formation.
You ascend with the "normal" ascending skills you are capable of--both of you. Without the stress of short breathing hoses and your buddy bumping into you and being unable to swim with the short octo---the DIR config makes this ascent feel incredibly easy.
You should end up at the surface , in exactly the way you normally would....
***note*** in a real world use of air share, the DIR diver, seeing his buddy/wife at a low psi ( say 400 psi to his 1200 psi) would shove his primary over to his buddy, and they would both begin the ascent. At the surface, once you get close to the boat, this will mean your buddy can go back to their own air, for the final moments of exiting the water, where buddy breathing is more cumbersome.

Regards,
Dan Volker

TSandM
August 25th, 2008, 12:04 PM
First off, big kudos to you and your wife that you are practicing this stuff!

I think what you just learned is that executing a well-coordinated air-sharing ascent is not a trivial task. Can you imagine how that would have gone, had one of you actually BEEN out of gas? THIS is why practice is essential. If the procedure is smooth and stress-free in a practice situation, it's more likely to go well when it's needed.

The problem with doing an ascent in a vertical position is that every movement of your fins drives you upwards. So you can try to do the ascent negative, and swim up, but that's difficult to calibrate, especially if a good part of your attention is being used up by maintaining the airshare. Doing the ascent in a horizontal position means you do the ascent close to neutral, and especially if you are diving a drysuit, you can vent it while maintaining the air sharing. (This still requires practice!) But the problem with doing an air-sharing ascent while horizontal is that it's difficult to impossible to do it if you are sharing a 24" hose or a 36" hose. This is why a lot of people go to a longer hose (40", routed under the arm with an elbow connector, or 5', or 7').

As far as who controls the ascent, the diver with gas should be the one monitoring depth and calling the stops, because he's unstressed (assuming there are no other tasks to be done while ascending). But each diver should control his own buoyancy. Somebody's already made the observation that the OOA diver has no power inflator, which is true -- but if he over-vents, he CAN orally inflate (another skill nobody practices).

Finally, it's my experience that depth gauges aren't terribly accurate, and no two read precisely the same at a given depth. If one diver is calling the deco, he says, "Level off HERE", and it doesn't really matter if the other diver's gauge is at 10 feet or 12 feet or 9 feet, that's where you level off and stay.

Again, this is wonderful that you guys are practicing this stuff, and as you solve the issues, I think you will find the polished skills that are required will be reflected in your normal diving, as well.

Theunis
August 25th, 2008, 12:46 PM
Hi Deefstes, you have received good advice from the members. The one donating the octo will not always control the ascent. You will find that the more experience diver will tend to take over control of the ascent.

The secret is to control the ascent by controlling your buoyancy. You should try to use your BC as little or as conservatively as possible. For me it's the easiest to do the ascent in a vertical position with my buddy facing each other especially in an emergency situation. This works great when you are sharing air with one reg or where your octo hose is too short.

You and your buddy should rather be a little negative than positive buoyant as well. It's better to have a slight finning action to neutralise negative buoyancy than having a battle with positive buoyancy. When you get to your safety stop depth you can fix your negative buoyancy by conservatively inflating your BC.

Remember, practise makes perfect!!

Blackwood
August 25th, 2008, 01:26 PM
You and your buddy should rather be a little negative than positive buoyant as well. It's better to have a slight finning action to neutralise negative buoyancy than having a battle with positive buoyancy. When you get to your safety stop depth you can fix your negative buoyancy by conservatively inflating your BC.

IMO, it's better to shoot for dead nuts neutral rather than slightly negative or slightly positive. Err on whichever side you feel is more cautious. If you're over a 4000 foot floor, positive may be more cautious than negative.



Remember, practise makes perfect!!

Definitely. I prefer to do my ascents and descents horizontally, as it's much easier for me to control when drag is working in my favor. However, whatever you and your buddy decide to do, practice it often.

Teamcasa
August 25th, 2008, 02:35 PM
Like others have said, kudo’s for doing the drill.

Just a few more thoughts. Doing a open water, no line assist stop is difficult for many divers even when they have plenty of air and almost impossible if one is panicked and out of air. Again, practicing is the best method to manage the panic factor.

Despite running the risk of being flamed, I’d advise you to practice holding the stop while sharing air in a vertical position. It is much easier. You can watch each other face to face, keep close, hold on to each other and control the stop and assent, further reducing the panic factor. Besides, should you ever have to do this for real with someone really OOA that has not trained with you, chances are they will be vertical and heading directly up to the surface. You will need to be the calm one, control the assent and instill confidence right away. Face to face helps with this. (Oh and take a rescue class together.)

Since, like me, your primary dive buddy is your wife, you have a big advantage. Practice and you both will eventually get this skill honed to perfection. While getting this done, and when doing your normal recreational dives, continue practicing the open water, no line assist stop in the horizontal position until both of you have that skill nailed. Then, add in the air sharing until it is also second nature.

String
August 25th, 2008, 03:09 PM
1. Throughout the exercise, we were in the vertical position. Sorting out our bad buoyancy would probably have been easier if were horizontal but in a real life emergency I'm pretty sure at least one diver will not remain horizontal. Your thoughts? What is a good position for an air sharing ascent?

If using standard length octo hoses face to face and vertical is about the only way the hoses will reach.



2. Keeping on the topic of body position, I found that donating an octo made things pretty tricky. We had planned on grabbing each other's BC's with the one hand, facing each other but the awkward looping of the octo hose made that, well, awkward.

Consider mounting the octo so it comes from your left. That way its the correct way up for the buddy without having to loop the hose. Those few extra inches help a lot.
I always use and teach grabbing the BC straps - i HATE the insecure roman handshake thing that so many people seem to do these days. Both should be securely grabbing each others BCs and hold each other close - too far away and its hard to not wobble all over the place.



3. Both of us kept a close eye on our computers throughout, mostly to keep a tab on our depth. We both had the same computer but even so, they didn't give he exact same readings all the time. So while she thought we we're at 5.4m, I thought we were at 4.6m (this is probably because of the 20sec sample interval).

Unlikely - sampling interval is for downloads only - they update once a second or so on a dive but only store snapshots at 20 seconds or whatever its set to. Very few computers read the same but most are only out by 20-30cm not that much.



The thing is I'd be trying to get us deeper while she'd be trying to get us shallower or vice versa. Would it perhaps be a better idea for both of us to keep an eye on just one of the computers?

Neither. The stop depth is not critical. Just get to somewhere you are both happy then signal stop. Then one of you watch the depth, the other base the position relative to the other diver without watching a computer at all. Constantly "chasing the needles" causes bouncing.



4. Would it not perhaps be a good idea for only one of the two divers (the one who is not OOA, ie. the donating diver) to manage the entire ascent? In other words, the receiving diver has only two tasks, keep the donated octo in your mouth and hold on to the donating diver's BC. The donating diver then makes sure the collective buoyancy is correct and manages the safety stop, monitors the computer etc.

The guy with air dictates it to an extent but the OOA diver will still need to dump from their BC and suit. The way its done here is the with-air diver has the computer, is responsible for the rate and so on, the OOA diver is responsible for staying level with the guy who has air (by looking at him NOT the computer).

Also worth noting that if it had been real after all the air had been dumped and you both ended up back at 15m your OOA buddy would not in the real world have been able to inflate their BC easily to get back off the bottom.

Try this a lot and shallow until comfortable before doing any more diving - if you cant manage a practice OOA ascent with no stress at all its not real safe to be there.

Blackwood
August 25th, 2008, 03:53 PM
If using standard length octo hoses face to face and vertical is about the only way the hoses will reach.

It's been quite a while since I've worked with a standard length hose, so forgive my confusion...

how so? It seems like the length of the hose will only dictate hose close together you must remain, not what position you're in. If you can share air vertically, couldn't you both rotate your bodies to horizontal, the donor's valve and the recipient's head the axes of rotation?

Awesome illustration, hose length is the same in both pictures:

http://www.scubaboard.com/forums/attachments/basic-scuba-discussions/49139d1219694321-air-sharing-ascent-1.jpg

george w
August 25th, 2008, 05:00 PM
My wife and I have practised the ooa shared accent many times. The weekend after the practise we were in the ocean at 70 feet. (long story) I ran out of air for real. Because we had practised this it was like we were just doing a drill. I told her I was out of air and she gave me her octo. We each held each others BC and started the accent, including the safty stop. Had we not pactised it who knows how it may have worked out. I cant stress enough how important it is to pratise this. Even for very experinced divers, pratise is a wonderful thing. Then hope to never need the skill.

Teamcasa
August 25th, 2008, 05:12 PM
My wife and I have practised the ooa shared accent many times. The weekend after the practise we were in the ocean at 70 feet. (long story) I ran out of air for real. Because we had practised this it was like we were just doing a drill. I told her I was out of air and she gave me her octo. We each held each others BC and started the accent, including the safty stop. Had we not pactised it who knows how it may have worked out. I cant stress enough how important it is to pratise this. Even for very experinced divers, pratise is a wonderful thing. Then hope to never need the skill.


It is so much better to read this type of post here and not in the accidents and incidents forum.

Deefstes
August 26th, 2008, 06:00 AM
Jeez, guys. Thanks so much for all the excellent advice. I'm not a big fan of diving in the quarry but now I'm actually really looking forward to our next session so we can go over the tips you gave.

Based on your tips I think the key mistakes we made were:
1. To start the ascent as soon as my wife had the octo in her mouth. I think we'll agree to a three step or four step (or however many steps) plan for this drill. In other words, break it down into small manageable components and not continue to the next step until we're both happy that the first step has been done properly.

2. We had no point of reference (like a SMB line or something) and kept "chasing the needles" (I like that expression).

3. Both of us tried to exercise control over our ascent and safety stop. In future we'll make a point of identifying one diver as the driver and the other one as the passenger. I can't imagine many situations where the passenger wouldn't be the OOA diver but I think we'll just find a hand signal or something with which to communicate that under water.

Again, thanks for all the excellent advice, I never cease to be impressed by the expertise I see on ScubaBoard. I think it should be a treat to actually see you guys in action;)

String
August 26th, 2008, 07:22 AM
Its worth doing without a point of reference - in the real world an OOA is unlikely to happen next to a shot line and its unlikely you're going to want to send a DSMB up with a diver within 6" of your face who is OOA.

TSandM
August 26th, 2008, 12:25 PM
String is right. Practice deploying an SMB as a separate skill; I think you'll find that it's not something you are going to be able to do while you are holding onto your buddy a few inches away, and trying to manage an ascent. We send up bags while doing air-sharing ascents all the time, but we dive a different equipment configuration and have different procedures, so that we have both hands free while sharing air. It's still a lot of task loading, managing an air-sharing ascent and deploying a bag.

Diving in relatively shallow depths (recreational) in the daytime, you always have some degree of reference for up and down. Up is where it's getting lighter; down is where it's dark :) At night, this becomes considerably more complicated.

tflaris
August 26th, 2008, 03:40 PM
I'd like to get your thoughts and advice on air sharing during ascent. Let me start by explaining where I'm coming from.

This weekend my wife and I decided to do some skills practicing at the local quarry. We wanted to look at some basic trim issues etc. but also to do air sharing while doing a free ascent with a 3 minute safety stop at 5m.

What a disaster! We started our free ascent at 15m and as soon as my wife took my octo, she became a cork. I'm sure it has nothing to do with using my octo but just that she forgot to mind her buoyancy. I grabbed her by the fin and pulled her down and at the same time dumped all the air from my BC. We must have been at around 10m by the time our upwards movement stopped and I'm surprised that our computers didn't complain of ascent rate violations so it couldn't have been too bad. By now she's realised what happened and she dumped all her air as well and before we knew it, we were back to 15m.

After some heavy finning and air additions to the BC's our buoyancy was sorted. OK, so we started the intended ascent. Things seemed fine although I think it could have been better. We didn't really ascend steadily but rather bobbed up and down with a net upwards movement, probably not ideal but not catastrophic either. The same thing continued through the safety stop and our 3 minute stop constantly varied between 4m and 6m.

If this was a real life emergency I think we'd have survived, even without harm. However, in a real life emergency at least one diver will probably have been much more panicked and things could have been much worse so I think we'll go back and practice this again until we get it right.

Now, your help and advice please.

1. Throughout the exercise, we were in the vertical position. Sorting out our bad buoyancy would probably have been easier if were horizontal but in a real life emergency I'm pretty sure at least one diver will not remain horizontal. Your thoughts? What is a good position for an air sharing ascent?

2. Keeping on the topic of body position, I found that donating an octo made things pretty tricky. We had planned on grabbing each other's BC's with the one hand, facing each other but the awkward looping of the octo hose made that, well, awkward. So we ended up being almost side by side, her to my left. Again, what is the correct way?

3. Both of us kept a close eye on our computers throughout, mostly to keep a tab on our depth. We both had the same computer but even so, they didn't give he exact same readings all the time. So while she thought we we're at 5.4m, I thought we were at 4.6m (this is probably because of the 20sec sample interval). The thing is I'd be trying to get us deeper while she'd be trying to get us shallower or vice versa. Would it perhaps be a better idea for both of us to keep an eye on just one of the computers?

4. Would it not perhaps be a good idea for only one of the two divers (the one who is not OOA, ie. the donating diver) to manage the entire ascent? In other words, the receiving diver has only two tasks, keep the donated octo in your mouth and hold on to the donating diver's BC. The donating diver then makes sure the collective buoyancy is correct and manages the safety stop, monitors the computer etc.

What else can you gurus tell me? I think this might be a valuable skill to master and once we have this one down pat we'll move on to buddy breathing during free ascent with a safety stop.

Pratice using the rule of thirds. Divide your total PSI of your tank into 3 equal parts. Use 1/3 of the total PSI swimming out (always against the current unless it is a drift dive). At your pre-determined turn pressure head back to your starting point. You should use no more than 1/3 of your gas supply to return to your starting point and this allows for 1/3 of your air supply for emergencies such as air sharing, lost buddy, lost boat, etc and allow for a safe careful ascent to the surface after a safety stop.

Hope this helps.

Rick Inman
August 26th, 2008, 03:55 PM
String is right. Practice deploying an SMB as a separate skill;
Actually, I think you were already practicing two separate skills together, and breaking them down might help.

Doing a "blue water" ascent facing each other, staying together, face to face (horizontal, hopefully), maintaining the same depth, moving together and holding together at 15' for three minutes - without sharing air, is a daunting enough task. Personally, I would practice doing that first, and then add the air share.

Like the others have said, good on you for practicing the drill!

nolatom
August 26th, 2008, 04:30 PM
I did it once not as a drill but because a buddy was low on air at about 75 feet.

There was no problem with my recreational-rig gear, I offered and he took my octo and grabbed my left BC strap. Yes, we were a bit ragged on dumping air and ascending since it's not that easy to synchronize, but it wasn't a serious problem, we figured it out as we went. We made the safety stop, by which time my pressure was down to about 300-400, same as his; then we ascended and he used his primary as soon as we surfaced.

Was I just lucky?

Soakedlontra
September 26th, 2008, 03:16 PM
I am a newly certified diver and I would like to practice air share with a controlled ascend with my buddy. Every time I bring up the subject he hesitates and shows some uneasiness particularly about the controlled ascent. He is fine in practicing air share but without ascending.

I think this drill has to be practiced fully not half way just sitting comfortably at the bottom.

What is the optimal depth to practice air share without putting ourselves in danger?

(During the classes we practiced our drills at a depth of about 20feet)

String
September 26th, 2008, 04:49 PM
Start shallow then work deeper. Remember most buoyancy changes are in the last 10m or so so that's the hardest point to actually control an ascent (and most dangerous).

Start off on dives a LONG way inside the NDL or even at the start if really shallow. Ideally do it next to a line initially because if it goes wrong you can both grab that line to stop the ascent.

The more hesitant someone is to do a skill generally means the less confident they are in doing it meaning all the more reason TO actually do it. And yes AAS should always be with ascents - after all if its needed for real the whole point is to get to the surface. Kneeling down achieves nothing.

Ben_ca
September 27th, 2008, 12:03 AM
String is right. Practice deploying an SMB as a separate skill; I think you'll find that it's not something you are going to be able to do while you are holding onto your buddy a few inches away, and trying to manage an ascent. We send up bags while doing air-sharing ascents all the time, but we dive a different equipment configuration and have different procedures, so that we have both hands free while sharing air. It's still a lot of task loading, managing an air-sharing ascent and deploying a bag.

Diving in relatively shallow depths (recreational) in the daytime, you always have some degree of reference for up and down. Up is where it's getting lighter; down is where it's dark :) At night, this becomes considerably more complicated.


Actually, I think you were already practicing two separate skills together, and breaking them down might help.

Doing a "blue water" ascent facing each other, staying together, face to face (horizontal, hopefully), maintaining the same depth, moving together and holding together at 15' for three minutes - without sharing air, is a daunting enough task. Personally, I would practice doing that first, and then add the air share.

Like the others have said, good on you for practicing the drill!


I agree 100% with Lynne and Rick.

A couple of thoughts to add:

Never Lose Situational Awareness: Always keep in mind what you are doing, where you are and what your (and your buddy's) gas situation is. you might run out of gas before you can move....

Take Things in Small Steps: If you are not proficient in shooting an SMB do not combine it with an OOA drill (or an actual OOA). If you get too task saturated and focused on the bag shoot (Must Shoot Bag!!!) you might actually overstay your welcome and run low (worse: out) of gas while you are messing with the bag. Even experienced divers have to weigh what to do.... It all goes back to Situational Awareness.

DA Aquamaster
September 27th, 2008, 08:28 AM
A few thoughts..

Re-read Danvolker's post and seriously consider it. Most recreational divers could easily incorporate a 5' or 6' long hose primary and bungeed octo into their configurations. I have never practised an air share with a recreational diver using my long hose where they did not quickly become a convert to the idea. It is infinitely easier and eliminates nearly all the problems you encountered.

I am confident that even with institutional inertia and legions of PADI and SSI short hose trained divers, DM's and instructors that the long hose primary will be standard in 10 years just like the use of an octo slowly became standard in the 70's and early 80's as the successor to buddy breathing (if you think an OOA air ascent with an octo is hard - try doing it while sharing a single second stage on a short hose.) Times change and equipment and standards change as better procedures evolve. So feel free to get ahead of the curve and use a long hose to make air sharing more practical in the real world.

Another thing to consider is that the odds are good a real life air share will not occur with your spouse. I have had 3 of then in the real world over 25 years and 2 of them were not my buddy and both of those involved being mugged for the primary. So learn to donate the primary as that is most likely how it will happen as the panicked or semi-panicked OOA and not your buddy diver will go for the reg currently making bubbles as he or she will want to make his or her own bubbles RIGHT NOW. Again a long hose primary aides this process as the hose is long enough that it does not feel like it is going to be pulled from the OOA diver's mouth, helping to calm them down - and it is the one they will have grabbed anyway.

The donanting diver in a short hose air share needs to manage the ascent as the OOA diver may well be panicked and unable to do it effectively themselves and or may want to claw their way to the surface immediately. So you need to be in charge and if needed, feel free to dump gas from the OOA diver's BC using their inflator or pull dump.

Again ascents are easier with a long hose as it is possible and even easy to swim in a normal horizontal position. Once the OOA diver calms down (access to air not at risk of being pulled away, direct eye contact, a minute or two to think etc all work wonders) you can do exactly that.

Mid water ascents can be managed my watching the smallest bubbles - they ascend at 30-60 fpm. Find one and stay level with it as it rises. Just remember to keep switching to smaller bubbles as you ascend as they get bigger as they go up and as they get bigger they go faster.

Shooting a bag works great for mid water ascents, but as noted above, it is not a skill you can do without practice and it is not something you even want to consider if you are face to face short hose air sharing with an OOA diver. If you try it, someone is going to get tangled in the bag and you will both get drug to the surface.

Delpoying an SMB is an option on a long hose, once both divers are stabilized and in a normal swimming postion.

A long hose also makes it very easy to share gas with a diver getting low on gas. If you have 1200 psi and your hoover air hog buddy has only 400 psi, a long hose air share get allow both of you to swim normally back to the anchor line and prevent the need for a mid water ascent and or a long surface swim back to the boat. More importantly, it ensures the low on air diver will have enough gas of his own to do a normal ascent on the anchor line, or just from the safety stop if they are really low on gas, with a normal BC inflate on the surface.

In fact if your regular buddy is a consistent hoover and you consitently come back aboard with a half tank more of gas, planning to share gas for a few minutes on the bottom in the middle of the dive is good practice and can be used to even out the gas consumption and can extend your bottom time as a buddy team.

The SA comments above are important. An OOA buddy at the end of the dive when you only have 500 psi could leave you both screwed. Keep a larger reserve in mind with new buddies and insta buddies and watch their gas supply until you are comfortable with how their gas consumption compares to yours. If you get lucky there SAC will match yours, if not, you should still be able to predict what they have by what you have left - just comfirm it now and then. If you both screw up and get in that situation where you only have enough gas to get one of you to the surface, that person is you and the other person is just gonna have to do an emergency swimming ascent. Life's hard sometimes and the priority needs to be not getting two people hurt or killed. Double fatalities related to OOA events are distressingly common due to a combination of poor skills, short hose air share challenges and poor situational awareness that allows a preventable problem to develop in the first place and a unwillingness or lack of mental preparedness to cut your losses when they need to be cut.

Over the years, I have gotten very good at noting my buddies SPG without them realizing I am even looking. Look at it on the boat and note where the needle position will be relative to the hose axis at full, half and 500 psi. Then you don't even have to read the numbers to have a good idea how much gas they have and you can note the SPG reading from 10 ft away if you need to. If swimming beside a new diver you can usually even rotate their SPG to look at it without them noticing. This is important if you note they are not looking at it. Knowing they turned a dive due to being low on air when you still have 2000 psi left is important information for subsequent dives so be sure you get that clarified either in the water or back on deck.

Also be familiar enough with their computer to know their deco status. Know what numbers equals remaining bottom time. Again this requires some looking on the boat and maybe asking some questions. Different computers can give markedly different bottom times.

Asking the buddy for their SPG reading is one very good way to prompt them to look at it and to help them develop the habit of looking every few minutes. I prefer one handed number signs and they can be taught to just about anyone on the boat in a couple minutes. You can use an ASL format or you can use the simpler format popular with technical divers. (Numbers 1-5 with the fingers vertical, numbers 6-9 with the fingers horizontal - for example seven would be two horizontal fingers - horizontal hand = 5 plus 2 more fingers for 7.)

Soakedlontra
October 2nd, 2008, 01:18 PM
I

The guy with air dictates it to an extent but the OOA diver will still need to dump from their BC and suit. The way its done here is the with-air diver has the computer, is responsible for the rate and so on, the OOA diver is responsible for staying level with the guy who has air (by looking at him NOT the computer).

Also worth noting that if it had been real after all the air had been dumped and you both ended up back at 15m your OOA buddy would not in the real world have been able to inflate their BC easily to get back off the bottom.

Try this a lot and shallow until comfortable before doing any more diving - if you cant manage a practice OOA ascent with no stress at all its not real safe to be there.

Last week my buddy and I practiced air share at a depth of 21 feet. I was also testing an AIR2 Ladyhawk BC and Man! It was hard to deal with the AIR 2.

During my OW classes the instructor told us that both the needer and the donor has to be neutrally buoyant before starting the controlled ascent. Well when I tried to orally inflate the Ladyhawk it was a nightmare! After the first attempt we decided that it was too hard and only my buddy became somewhat buoyant.

It took us a while to get started the controlled ascent (apparently I was not kicking hard enough). During the ascent we where not looking at each other face at all!. I could see my buddy's waist and he could see the top of my head!. I had a feeling that he was ascending too fast so I kicked more slowly than him. He kept looking at me and signalling to go up but I sticked to my guns. Well after surfacing he told me that his computer (I don't have one) beeped to let him know that he was ascending too fast...

Once on the surface I tried to orally inflate the BC and it was another nightmare. The surface was choppy and small waves kept splashing on my face. But the biggest problem was being able to keep the valve under the AIR 2 closed with my hand. It was almost impossible. I managed to get some air in the BC but not enough to keep my head completely above the water. After several attempts I gave up and pressed the inflator button. In a real emergency situation I bet that it would have been really difficult not to get stressed out and keep the situation under control.

That day we certainly learnt that we do need to practice air share over and over again until we are not so clumsy anymore and have a better air-share plan discussing all possible scenarios in case things go wrong.

zeagle911
October 2nd, 2008, 02:59 PM
Well done for practising your skills, but it looks like you are both newly qualified divers. OOA ascents require a number of skills to be carried. The main being bouyancy control, especially if you do not have a reference. Conducting a joint safety stop, is very different than carrying out one by yourself.
Maybe it would be better if you practiced these skills on there own before you try to combine them.
Sounds like you kept you cool under preasure, so well done and keep it up.

Soakedlontra
October 8th, 2008, 12:33 AM
Well done for practising your skills, but it looks like you are both newly qualified divers. OOA ascents require a number of skills to be carried. The main being bouyancy control, especially if you do not have a reference. Conducting a joint safety stop, is very different than carrying out one by yourself.
Maybe it would be better if you practiced these skills on there own before you try to combine them.
Sounds like you kept you cool under preasure, so well done and keep it up.

Well, that's what we ended up doing last weekend. There was too much to deal with. I was testing new gear (I borrowed my buddy's Back Plate/Wing set up with a longer hose attached to the primary first stage) and trying to do air share and a controlled ascent at the same time. So after our first air share with a failed controlled ascent we decided to break up the skills. We haven't even dealt with a joint safety stop yet!

We concentrated on the controlled ascent and tried it several times. We did the first one without a point of reference. It was hard to even understand whether we were moving upward at all or not! I tried to follow the bubbles but I got rather mixed up. There are some many of them! But I definitively did not keep up with the fastest ones!

The other two times we had a wall as a reference and it was better. We ascended at a proper speed, not because I mastered the 'bubbles chasing game' ( it is going to take a lot of more tries before I will get that straight!:confused:) but because my buddy kept a close look at his computer.

The challenge goes on!

Happy diving:)

Deefstes
October 8th, 2008, 05:52 AM
Good on you. My wife and I have not had the opportunity to practice an air sharing ascent again since but on our safety stops we now hold on to each other to practice a joint safety stop. I find that it works a bit easier if only one diver "controls" the stop.

In other words, if it is important that the two divers be close during the safety stop (such as in an air sharing scenario), it might be easier if one diver relies on the other to control their combined buoyancy. But that's just me and I'm still very much a noob myself.

Soakedlontra
October 8th, 2008, 02:04 PM
Good on you. My wife and I have not had the opportunity to practice an air sharing ascent again since but on our safety stops we now hold on to each other to practice a joint safety stop. I find that it works a bit easier if only one diver "controls" the stop.

In other words, if it is important that the two divers be close during the safety stop (such as in an air sharing scenario), it might be easier if one diver relies on the other to control their combined buoyancy. But that's just me and I'm still very much a noob myself.

My dives so far have been from shore and during the safety stop my buddy and I get negative buoyant and hang at the bottom. There is no problem in staying close to each other. We haven't practiced a safety stop in the water column yet. We may end up having to hold to each other, though.

Lately every time I go diving I test a different kind of gear because I am still figuring out what kind of equipment is more suitable for me to buy. I used an integrated AIR2 BC one time and last weekend I tried a Back Plate/Wing set up. I may make my life more difficult in doing so because I have to get familiar with different configurations and practice the skills. However I think it is important that the gear has to function properly and be reliable in emergency situations.

Practicing skills and getting good at them is also a way to increase my self-confidence and hopefully it will help me to reduce the risk of panicking if an emergency occurs (let's touch wood!).

In my little experience I think that ideally each diver has to take the responsibility to monitor and control its own buoyancy and not to rely to the other to do all the work. In a share air scenario the needer won't probably be capable to think rationally and will tend to rely more on the donor. The few air share I have practiced so far and the following discussions with my buddy, are teaching me that it is important to take time to calm down the needer once the air situation has been stabilized and remind him/her to control his/her buoyancy and keep an eye on the speed of the ascent. Once that is done then the divers should begin the controlled ascent, hopefully without a panicked needer.

miketrance84
October 8th, 2008, 03:04 PM
On ascent start at 15m , you pass your long hose primary to your wife, with you switching switching instantly to your necklace reg.
You are now swimming comfortably side by side, not bumping into each other, or even slightly hampered--it is exactly like being on your own air supply, and swimming in a buddy formation.


IMO Swimming face to face in a real OOA emergancy is essential. I think that the reassurance of human contact really calms people down and allows the OOA diver to relax and concentrate on maintaining bouyancy. My dive buddy (my wife) and I practice this skill on every day we dive. If you dive with the same buddy you can pretty much do it either way as long as your both comfortable.

Soakedlontra
November 21st, 2008, 05:17 PM
At last I have my own equipment! A DSS BP/W with a longer hose and an octopus attached to my neck with some surgical tubing.

We have been practicing air share with a controlled ascent and we are slowly getting better at it. We have split the drill into two so for now we are practicing the air share and the ascent separately. The longer hose does make a difference, we can keep eye contact all the time without twisting our necks.

The last time we practiced the controlled ascent in the water column with the help of a surface marker buoy at 28 ft. It was the third time that my buddy used it. It took a little bit of fiddling with the reel and the string to release it to the surface. It wasn't too bad. We did a safety stop at about 15ft hanging on that string.

I feel this is only the beginning...



A few thoughts..

Re-read Danvolker's post and seriously consider it. Most recreational divers could easily incorporate a 5' or 6' long hose primary and bungeed octo into their configurations. I have never practised an air share with a recreational diver using my long hose where they did not quickly become a convert to the idea. It is infinitely easier and eliminates nearly all the problems you encountered.

I dived with a different buddy who had regular hoses etc. a while ago for the first time and when I showed him my longer hose he was a bit perplexed and, perhaps, uncomfortable but he did not refuse to dive with me. I think it is going to be hard to find new buddies with 'standard' gear who won't freak out at the sight of a longer hose...

DA Aquamaster
November 21st, 2008, 05:47 PM
I agree, it takes a bit of salemanship to get them to try it the first time. Once they try it though it is very common for the diver to be an instant long hose convert.

Soakedlontra
December 3rd, 2008, 01:51 PM
The only problem with the longer hose is that it tends to get entangled on the snorkel...Well I admit I still use the snorkel, it is a bit like a security blanket for now, I guess I am not ready to get rid of it yet (it may have something to do with the fact that my air consumption is still so high...).

However I noticed that if I keep practicing 'unwinding' the hose around my neck during air share with a wider swoop I can avoid this hassle.

I can see why so many divers do not use it, though.

orange_diver
December 3rd, 2008, 03:00 PM
to add to the good advice you've already gotten:

1. practice this skill at the beginning of your quarry dives not the end in case of ICBMing to the surface

2. when you first donate to the OOA diver take a full minute at depth to get sorted out: position, trim, neutral buouyancy, calm attitude. the emergency is over, no need to rush, after everyone is settled there should be a non-eventful ascent.

3. make sure in your gas planning you have enough rock bottom to bring you and your buddy to the surface, and include this one minute in your gas planning. if "rock bottom" is an unfamiliar term to you, do a search here and you will be greatly rewarded.

orange_diver
December 3rd, 2008, 03:01 PM
It's been quite a while since I've worked with a standard length hose, so forgive my confusion...

how so? It seems like the length of the hose will only dictate hose close together you must remain, not what position you're in. If you can share air vertically, couldn't you both rotate your bodies to horizontal, the donor's valve and the recipient's head the axes of rotation?

Awesome illustration, hose length is the same in both pictures:

http://www.scubaboard.com/forums/attachments/basic-scuba-discussions/49139d1219694321-air-sharing-ascent-1.jpg

i'm not diving with someone who's using red hoses blackwood. :no:

Deefstes
December 4th, 2008, 02:57 AM
i'm not diving with someone who's using red hoses blackwood. :no:

Yeah, that'll take some salemanship too.

torqd
December 7th, 2008, 12:10 AM
Last week my buddy and I practiced air share at a depth of 21 feet. I was also testing an AIR2 Ladyhawk BC and Man! It was hard to deal with the AIR 2.

This is one of the most challenging things I have learned to work with as well. Please keep up practicing the use of the AirSource 2 if you are going to continue diving with one as your alternate. This basically requires you to remove the mouthpiece while exhaling to vent the BCD if you don't have a dump valve on the right shoulder. I've heard that the AirSource 3 is redesigned so that this may not be required, but I have not worked with one to know for sure, or how it does this.

Also to note is that your primary hose is (probably) shorter than the standard octo hose, so being very close is necessary.


Once on the surface I tried to orally inflate the BC and it was another nightmare. The surface was choppy and small waves kept splashing on my face. But the biggest problem was being able to keep the valve under the AIR 2 closed with my hand. It was almost impossible. I managed to get some air in the BC but not enough to keep my head completely above the water. After several attempts I gave up and pressed the inflator button. In a real emergency situation I bet that it would have been really difficult not to get stressed out and keep the situation under control.

This is simply something that you have to practice to get down. Using your fins to kick up to gulp air in, then slide back down as you inflate the BCD. Practice this in calm conditions first and then work into the rougher conditions.

If all else fails, remember that in a real emergency if you can't orally inflate the BCD to dump your weights to get positive on the surface!

BlueDevil
December 7th, 2008, 02:17 AM
Some great discussion here...thanks to all contributors.

Another point for consideration is that with a panicking diver it may be best to skip the safety stop. I am assuming here that this a no-stop rec dive, and that while a stop is highly desirable it is not be essential. Imagine trying to hold a stop with a badly panicking diver! The best place for them is on the surface with their BC well inflated (you may have to orally inflate it for them, or drop their weights).

For those using standard length occy hoses I would give strong consideration to putting a swivel on the reg. This allows the reg to be donated to a diver in virtually any position. I know DIR advocates would say this adds an extra failure point into the system, but I have used them for many years without any problems. It definitely makes air sharing very much easier (and therefore safer). Even though I personally use a 5ft hose I still have a swivel on it. Have shared on three or four occasions and it works very well.

sibermike7
December 7th, 2008, 02:44 AM
Some great discussion here...thanks to all contributors.

Another point for consideration is that with a panicking diver it may be best to skip the safety stop. I am assuming here that this a no-stop rec dive, and that while a stop is highly desirable it is not be essential. Imagine trying to hold a stop with a badly panicking diver! The best place for them is on the surface with their BC well inflated (you may have to orally inflate it for them, or drop their weights).

Good point, but on the other hand, if they have managed to get to the safety stop, I doubt that he/she will still be panicking! ;)

And the SS may just be the step needed to further calm a person down. Nothing like a nice pause with a few skills to concentrate on. This focuses the mind. I have known of divers panic after surfacing (strange as it may seem!)

A safety stop is just another redundant safety measure and may not be necessary. However, as this is practice at this point, practice it.

However, as stated by BD, it may be a good idea to skip the SS if necessary.

I would also practice the drill vertical because that is the position most will assume in a stressful situation and also with a "pick-a-buddy" dive. If you get it down pat with the wife and go on to horizontal, just remember in the real world you'll have to be open-minded enough to adapt to the situation.
Great post!!!

Soakedlontra
January 5th, 2009, 07:40 PM
This is one of the most challenging things I have learned to work with as well. Please keep up practicing the use of the AirSource 2 if you are going to continue diving with one as your alternate. This basically requires you to remove the mouthpiece while exhaling to vent the BCD if you don't have a dump valve on the right shoulder. I've heard that the AirSource 3 is redesigned so that this may not be required, but I have not worked with one to know for sure, or how it does this.

Also to note is that your primary hose is (probably) shorter than the standard octo hose, so being very close is necessary.



This is simply something that you have to practice to get down. Using your fins to kick up to gulp air in, then slide back down as you inflate the BCD. Practice this in calm conditions first and then work into the rougher conditions.

If all else fails, remember that in a real emergency if you can't orally inflate the BCD to dump your weights to get positive on the surface!

Thanks for the info.

At the end I scrapped the idea of getting a BC with an AIR2.

I bought a DSS back plate and wing with a normal 16 inches inflator hose and a longer hose for my primary second stage and I have attached my octopus to a necklace made of medical tube, instead.

It works far better for me.:)

Soakedlontra
January 5th, 2009, 08:01 PM
Some great discussion here...thanks to all contributors.


For those using standard length occy hoses I would give strong consideration to putting a swivel on the reg. This allows the reg to be donated to a diver in virtually any position. I know DIR advocates would say this adds an extra failure point into the system, but I have used them for many years without any problems. It definitely makes air sharing very much easier (and therefore safer). Even though I personally use a 5ft hose I still have a swivel on it. Have shared on three or four occasions and it works very well.

I decided to use a 5 Ft hose too. I have been practicing air share with it that just few times so far (got a cold and for 4 weeks I could not dive). It still feels a bit cumbersome unwinding the hose from my neck but, as other divers have mentioned here, it is just a matter of practicing the drill to 'death' and I will be fine!:)

Two days ago I finally saw the kind of bubbles that I am supposed to follow during the ascent that everybody is talking about! Hallelujah!

coldsmoke
January 5th, 2009, 11:21 PM
http://www.scubaboard.com/forums/attachments/basic-scuba-discussions/49139d1219694321-air-sharing-ascent-1.jpg


i'm not diving with someone who's using red hoses blackwood. :no:

And I'm not diving with anyone who forgets their fins.:lotsalove:

On a serious note regarding the free ascents (just in case the original poster is still tuned in). Watch the particles. I find it much easier than watching the bubbles and as long as you have plenty of air slower is almost always better. And don't worry so much about a constant speed ascent. Start off neutral, take a slightly bigger breath and as you start to rise dump exactly one glug from your bc. :D (You'll actually learn to kinda feel how much air you dump) As you approach about 10 feet higher breath shallower and halt your ascent. Stop here, make sure you are neutral and repeat. Do this all the way to your safety stop or the surface. I try for a 30 second stop and a 30 second slide. Of course that's being anal but it give you a 10'/minute ascent with you might find you like.

Good luck and keep practicing.

Hunter

J.R.
January 5th, 2009, 11:57 PM
What a disaster! We started our free ascent at 15m and as soon as my wife took my octo, she became a cork. I'm sure it has nothing to do with using my octo but just that she forgot to mind her buoyancy. I grabbed her by the fin and pulled her down and at the same time dumped all the air from my BC.

Isn't one of the fundimental steps in sharing air to "hold on" to your buddy (or buddy's BC) to start with? If she went bouyant the extra drag (you) could have helped slow and stabalize... just a thought...

Soakedlontra
January 12th, 2009, 02:24 PM
And I'm not diving with anyone who forgets their fins.:lotsalove:

On a serious note regarding the free ascents (just in case the original poster is still tuned in). Watch the particles. I find it much easier than watching the bubbles and as long as you have plenty of air slower is almost always better. And don't worry so much about a constant speed ascent. Start off neutral, take a slightly bigger breath and as you start to rise dump exactly one glug from your bc. :D (You'll actually learn to kinda feel how much air you dump) As you approach about 10 feet higher breath shallower and halt your ascent. Stop here, make sure you are neutral and repeat. Do this all the way to your safety stop or the surface. I try for a 30 second stop and a 30 second slide. Of course that's being anal but it give you a 10'/minute ascent with you might find you like.

Good luck and keep practicing.

Hunter

Well so far I have been practicing the ascent in 20 ft of water and I do not do a safety stop in the water column. I guess I am taking 'baby steps' and it is going to take a while before I actually begin to practice a safety stop in mid water.

Everybody talks about being neutral before beginning the ascent. However I have found that being slightly negative gives me more control somehow. Is there any truth in this or it's just a 'false' impression?

---------------------------------------------------
Open Water Bubbles (http://openwaterbubbles.blogspot.com/)

TSandM
January 12th, 2009, 07:09 PM
Soakedlontra, the thing we all fear with ascents is getting too positive and losing control. If you do your ascent negative and vertical and swim upwards, this won't happen (or it's less likely). There are some problems, though -- It's harder to do a safety stop and hold it, if you are negative and constantly finning to maintain your depth. You can't get to your buddy very readily, if you are vertical and he has some horizontal displacement away from you. If you get distracted or something makes you stop finning for a moment, you will sink.

Doing your ascent in a horizontal position, and keeping your buoyancy always very close to neutral (getting just a little positive to rise, and then back to neutral to stop) means you are always in good control of your position in the water. It takes a little more practice, for sure, to get the sequence down, but I got a great piece of advice from jonnythan here on SB three years ago -- Take a deep breath and begin to rise, and then exhale it; if you don't stop, then vent something. Using this approach gave me my first foothold on a good, controlled, and close to neutral ascent. From this kind of ascent, stops are relatively easy to do, although getting them precise on depth and holding that precision still isn't easy for me today.

Soakedlontra
February 18th, 2009, 04:57 PM
Soakedlontra, the thing we all fear with ascents is getting too positive and losing control. If you do your ascent negative and vertical and swim upwards, this won't happen (or it's less likely). There are some problems, though -- It's harder to do a safety stop and hold it, if you are negative and constantly finning to maintain your depth. You can't get to your buddy very readily, if you are vertical and he has some horizontal displacement away from you. If you get distracted or something makes you stop finning for a moment, you will sink.

Doing your ascent in a horizontal position, and keeping your buoyancy always very close to neutral (getting just a little positive to rise, and then back to neutral to stop) means you are always in good control of your position in the water. It takes a little more practice, for sure, to get the sequence down, but I got a great piece of advice from jonnythan here on SB three years ago -- Take a deep breath and begin to rise, and then exhale it; if you don't stop, then vent something. Using this approach gave me my first foothold on a good, controlled, and close to neutral ascent. From this kind of ascent, stops are relatively easy to do, although getting them precise on depth and holding that precision still isn't easy for me today.

I have finally managed to practice ascending horizontally during my last two dives. They were my first boat dives. My buddy and I ascended along the anchor line. It went pretty well. Still I keep following my buddy's ascent rate instead of trying to figuring it out by myself by looking at bubbles or stuff suspended in the water. My buddy has the computer so it is inevitable that he becomes 'the ascent-rate leader'. I don't know how to solve this 'problem' a part from buying a computer...

Cheers

TSandM
February 19th, 2009, 12:45 AM
Well, if you are diving without any sort of depth gauge at all, you can't control your ascent rate, because you don't know what it is. I would highly, highly recommend obtaining some sort of depth gauge that gives you depth and elapsed time, even if it's just a watch. Then, if you know your depth, and you know the time, you can play to go up 10 feet in one minute, and if you get up ten feet in less than one minute, you wait there until a minute has elapsed, and then move up again.

BTW, even very experienced divers succumb to the trap of matching their buoyancy to their buddy's, or to anything else they are watching. I was watching a lobster climb a wall in Southern California and was horrified to discover I had gone up about 15 feet without even noticing it! And I have caused a technical diver to flip over on his back by my poor buoyancy control, in my beginner days.

Deefstes
April 15th, 2009, 10:39 AM
Alright, seeing as this was originally my thread ;-) I guess I am allowed to revive it.

Last weekend my wife and I did some skills practice again and stepped it up a notch. We seem to have gotten the air sharing on ascent part sorted out now so we decided to try something else. In retrospect I think it was a stupid exercise as a situation in real life that would warrant it, would be far more catastrophic than we have training for anyway.

At any rate, what we decided was to do air sharing but leaving the entire ascent up to one diver - bit like a rescue situation. We took turns, one of us would act all limp and be dead weight while the other one would take him/her to the surface in a controlled fashion. We repeated the exercise once with the constraint that the "incapacitated" diver's BC could not be used to adjust buoyancy and once without that restriction. The restriction was intended to "simulate" a situation where the diver had complete equipment failure. The "incapacitated" diver would at least bite down on the octo so the "rescuing" diver didn't have to keep it in his/her mouth.

As I said, silly idea. We did discover a few things though and I just desperately hope that we will never find ourselves in such a situation in real life and that, if we did, there would be a properly trained rescue diver with us. It's not a trivial task!

1. We decided to do the ascent in a horizontal posture, facing each other. Totally impossible. The dead weight diver messed up the posture so quickly that it was pointless for the "rescuing" diver to try maintaining horizontal. We eventually did the ascent face to face but even so the "incapacitated" diver tended to slide under the "rescuing" diver so to speak.

2. We tried once with the "rescuing" diver behind, or in horizontal trim on the back of the "incapacitated" diver. This seemed to work better but this is certainly one situation where long hoses would be a great benefit. We don't have long hoses.

3. We decided that it was a futile exercise as a situation where one diver is incapacitated really is beyond our training and that we'd be better off practicing various OOA type scenarios but with two perfectly fine divers.

4. My wife hasn't bought into the idea yet but I certainly would like to do a rescue diver course. That won't happen very soon though as I should first try to get a lot of dives under the belt as AOW. By then my wife will probably agree to also do it.

DBailey
April 15th, 2009, 11:25 AM
I know mnay people learn this skill directly face-to-face. This leads to a couple of issues:

1. The "double back" effect of the alternate hose and regulator.
2. The space between the two divers gets really crowded with arms reaching across, kicking each other, etc.
3. The alternate hose all of a sudden gets a lot shorter.

Staying with the normal recreational gear set-up (i.e. short hose primary, donate the secondary), here is what I like to do...

1. The face-to-face aspect is great for the initial contact. Looking the OOA diver in the face and help calming them down in invaluable. But nothing says you have to stay in this position.

2. For the ascent, don't be face-to-face, but be offset a little to your left. Each diver should slide a bit to his/her left until each diver's right shoulder lines up.

3. For the grasping of the BCD or the "Roman handshake", each diver is now reaching straight out to the other diver's right side, instead of crossing over each other's body.

4. This alignment lessens the effect of the "double back" on the alternate hose. This alignment also lessens the amount of kicking into each other on the ascent if vertical. This position also frees up each diver's left side for bouyancy control and checking gauges.

Give this a shot and see if it helps some of your positioning.

For those that use the long hose, if I am reading the posts correctly, is there any physical contact between the divers once the air sharing begins?

Reg Braithwaite
April 15th, 2009, 11:59 AM
As you know, I have as little experience as you do. All I can say is that I've done a few of these drills to sort things like this out, and a HUGE congratulations to you and your wife for practicing together! My wife and I did a few pool sessions before a recent trip to Cozumel, and while OW practice would be better, it's amazing how much you benefit from doing the drills together. My wife and I practiced sharing on alternates AND sharing a single regulator. While this shouldn't be needed in the field, it's a fabulous drill for working out buoyancy kinks. I confess it humbled me the first time a training partner got me to do this drill while we hovered a foot off the bottom of the pool. It was so hard to maintain my position while passing a regulator back and forth!

Anyhow, right off the top I'll say that there is training you can get on this sort of thing fro UTD and GUE. They both have recreational programs, and the UTD folks will let you use most of your existing gear. UTD sells DVDs showing air sharing and ascents and so forth. Consider watching them as well.

A few things to think about. I was taught to ascend horizontally. A little googling will reveal that many people think this is important for preventing DCS, and as a bonus at no extra charge, it is much easier to control your depth. An air sharing ascent in the horizontal position would be much easier with a 1.6m or 2.1m long hose. Insert debate here. :popcorn:

Ascents are easier when you have a reference line. I was taught to use an SMB. A little practice with it quickly reveals that buoyancy control AND managing a string that can entangle you AND dealing with it bobbing on the surface is more task loading than just looking at a gauge. That's without tossing in air sharing.

The aforementioned training and videos will reveal that some people advocate sharing responsibilities: one person deploys the SMB while the other tracks depth and stops. Debate this point: Do you need two people staring at their computers? If they are off by a few feet, is it lower risk for each person to stop where their computer says to stop or is it lower risk to pick one and have both people stop together as a buddy team? In the case of air sharing, of course, there is no debate, both people ascend as a team, so only one need look at the depth gauge and signal when to rise and where to stop.

It's true that an OOG diver may be panicked at the outset of the situation, but if your practice this I would hope that you get to a place where if it happens for real, you are able to calm down once air sharing has begun and the OOG diver might be the best person to track depth so that the donor is free to manage the gas and possibly an SMB.

Just a few thoughts here, no advice to speak of :-;

p.s. Should you choose to investigate long hoses, you will find that they work just fine with all your existing gear and it's really very cheap to make the switch. You need not invest kilorands in back plates, wings, and canister lights.

TSandM
April 15th, 2009, 07:03 PM
Don't feel bad! Managing an unresponsive diver was one of the hardest drills for me in Rescue class, and remained challenging once I moved into doubles and "tech-ish" training. But there is nothing wrong with practicing this, and you learned a lot about ways that don't work very well, even if you didn't discover any that you thought worked better.

What I've been taught: Control buoyancy with the incapacitated diver's equipment. Managing your gear and theirs is too much, and you want them so that, if you get separated from them, they will not sink.

So, if you start with the position that the unconscious diver is positive and you are negative, one way to meld you two together is to put the unconscious diver UNDERNEATH you. If you jam their regulator(s) into about your solar plexus, they won't flip in front of you or twist around too much. You can grasp the tank with your knees, if they are in a single tank, and that gives you more control. Most unconscious people's feet will sink, which, if you are in a drysuit, helps you keep their shoulder vent high so their suit will empty as you ascend. Staying in a roughly horizontal position will allow you to swim forward as well as to rise, should you wish to get closer to shore or closer to the upline while you are ascending. Close to the surface, you let your feet drop and wrench the person onto their back and inflate their BC or suit or both, depending on what you have available, so they will float face up on the surface.

It's a good skill to learn, and a good one to practice, and I have to admit I don't practice it nearly often enough. That's probably because it IS hard to do, and we tend to avoid things that don't go well. But as Danny Riordan told me before our first cenote dive together, "Just because you don't do something well isn't a reason to avoid doing it. It's a reason to do it more often."

Rick Inman
April 15th, 2009, 09:06 PM
Most unconscious people's feet will sink, which, if you are in a drysuit, helps you keep their shoulder vent high so their suit will empty as you ascend.

Yeah, and don't forget to make sure their drysuit vent is all the way open. I had a tricky guy once close his all the way before I was supposed to rescue him - just to mess with me.

It did...

coldsmoke
April 15th, 2009, 10:13 PM
Humm - I wonder who that tricky guy was.

Hunter

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