On my last dive trip to the Galapagos, one of my dive mates highly recommended getting an SMB with a spooled line instead of the mouth-inflatable safety sausage I had (the liveaboard recommended them for the trip -- I'd never had one before). He said that he oftened deployed the SMB at 15', when he did his safety stop.
I have to admit that his SMB looked quite cool, particularly since you could inflate it with your second stage. But I'm wondering why one would deploy an SMB while still underwater. Can someone please explain?
Thanks in advance.
CalgaryDF
May 14th, 2010, 12:39 AM
Its deployed so the boat knows where you are while you do your safety/deco stops. It also keeps other boats aware of where you are, and provides you a reference for depth. If you are hanging on an anchor chain its probably not really necessary, however can be good if you get lost or have to ascend away from the boat.
fnfalman
May 14th, 2010, 12:39 AM
There are safety sausages and then there are surface buoy markers (SMBs). Safety sausages can only be inflated by mouth and generally designed to be blown up when you're on the surface already. An SMB can be deployed while you're underwater by oral inflation or by purging the second stage.
An SMB tends to be taller and wider. Either way, you use them to identify your location.
People usually deploy an SMB when they do their drift dives so that the boat can see where they're going and follow them.
People also deploy an SMB if they were in a dive and got swept away by current and couldn't find the anchor line. That way they can do their safety stop or even decompression stop and hopefully the boat can see them.
Some SMB/safety sausage comes only in orange. Some come in neon green/neon yellow. Some have reflective stripes, some don't. Some have pockets for mirror, whistle and light stick. Some have a pocket on the tip for attaching light stick/small flashlight/beacon light.
How much do you want to spend?
sabbath999
May 14th, 2010, 12:41 AM
There are many reasons one would use an SMB. One is that you deploy it on a drift dive so the boat can easily see where you are. Another is that you can mark your reel at 15 feet and use it to "hang on" to for your safety stop. Some can be used as a secondary lift bag as well.
There are other reasons as well.
You also don't need to shoot them from only 15 feet down, you can shoot em from about any depth you have the line for... in fact, it is easier to shoot them from 60 feet than 15.
TSandM
May 14th, 2010, 01:10 AM
I think the biggest purpose for deploying a bag at depth is that, if you know you are being carried away from the boat, you can get something on the surface to mark your whereabouts while you are still close enough to it for someone to see the marker. If you have to wait until you are on the surface, you may be a long ways from the boat, and they may have trouble picking you up, especially in unsettled seas.
The other reasons for deploying underwater are also valid, but the one above is the most urgent, I think. I have to say that, as a sometimes boat tender, it is tremendously reassuring when you see that bag come up, and you know where your divers are, and that they are okay.
Ben_ca
May 14th, 2010, 01:22 AM
The why is easy... actually doing it well takes some practice and training.
jtpoGCzVWZs
Crush
May 14th, 2010, 01:28 AM
But I'm wondering why one would deploy an SMB while still underwater. Can someone please explain?
Thanks in advance.
SMBs are typically used if required by law to mark a diver's location at all times during a dive. Hence, they are deployed at the surface prior to a dive and towed about. A rescue sausage is often deployed at depth and (depending upon its design) can be orally inflated, inflated with your reg, or both.
A rescue sausage can be used as an SMB - on a dive last year a passing boat cut the line between us and our SMB - we deployed a rescue sausage and continued on with the dive, in full compliance with all local ordinances. In addition to not being fined, our boat managed to keep track of us on a drift dive in very choppy water - had they not been able to stay with us, our extraction from the water may have been delayed.
At the surface an SMB or a rescue sausage can serve a welcome extra flotation in the event that your extraction is delayed. However, if you want to be spotted in choppy water, size does mater - get a long, bright rescue sausage.
In the (very unlikely) event that there is a catastrophic failure of your drysuit and/or buoyancy device, a rescue sausage can be rapidly deployed to "tether" you to the surface via the spool of line. Remember that a rescue sausage may have a buoyancy of about 25#, but a fit swimmer with fins will have a very difficult time raising 5# to the surface from depth. Summary: it is much easier to pull yourself up using a rescue sausage/spool than to swim up.
Final note: everyone has their own opinion on what kind of spool to use with a rescue sausage. I prefer a finger spool as, owing to its simplicity, it will not "jam." Once un-clipped, if the spool gets yanked out of your fingers it will continue to un-spool and may eventually fall past you as opposed to a cave-style reel which (if jammed) will rocket to the surface with your sausage. Finger spools are also smaller and cheaper.
Happy diving!
fnfalman
May 14th, 2010, 01:33 AM
And whatever you do, please stow the finger spool/cave spool properly or else you'll find out that it had unraveled and wrapped around your feet.
I've only seen it happened once, but if it had happened once, it'll happen again to somebody.
AfterDark
May 14th, 2010, 01:37 AM
The why is easy... actually doing it well takes some practice and training.
jtpoGCzVWZs
Wow that looks hard!:sarcasm: I bought one this season. Took it diving and deployed to try it out. Where does the training come in? Is there a PADI course for that?
Crush
May 14th, 2010, 01:39 AM
Wow that looks hard!:sarcasm: I bought one this season. Took it diving and deployed to try it out. Where does the training come in? Is there a PADI course for that?
There is a PADI course for everything! I am taking "underwater battery changing" this weekend. :)
clifftondiver
May 14th, 2010, 02:12 AM
It seems everyone has covered the uses of SMBs. One point, however, that hasn't been mentioned. Be mindful of your depth vs. line-length on your spool (whichever kind you use). For example, you don't want to be deploying your SMB from 115' (did it 2 weeks ago) when you only have 100' of line (or however long it may be).
Should you have a Manta Reel, take the time and effort to measure how much line you have. Of all of my dive buddies, (we all bought them for a wreck class) not a single one had the advertised line-length!:angrymob:
SMB's should be a regular piece of your rig, IMHO.
As far as difficulty, it's not complicated. But it does require practice to deploy while maintaining your depth.
I particularly liked the point he made about not putting your finger to hold the reel because if the SMB gets caught up in something it could very well just break it!
veg123
May 14th, 2010, 04:33 PM
excellent video above. We use an SMB all the time from 20ft off local RIB. It takes a lot of getting used to, I was afraid to deploy for a long time, and I had to overcome the fear, but after I got used to it I now feel slightly exposed hitting the surface without one.
I prefer to be slightly negative when I start to deploy. I find it easier to correct been slightly more negative as opposed to slightly more positive.
One other thing... if the balloon hits the surface and you don't pull the line tight it can start to sink again. If this happens do not try to fin up to the balloon to correct it. Sit tight, let the balloon sink, and be careful not to get entangled in the line as it will sink along with the balloon.
It's definitely a skill that needs to be practiced, I went to the pool a couple of times to get the hang of it.. but do it a few times and it'll just feel like part of the dive.
Doc Intrepid
May 14th, 2010, 04:43 PM
If you purchase a closed-circuit SMB it can also be used as an inflatable at the surface to support a diver in distress. Some work better than others for this purpose, but depending on the nature of the problem they can be handy in numerous situations.
http://www.halcyon.net/?q=node/11
(Open-circuit SMBs are the ones that can collapse at the surface if not properly weighted...OTOH they make useful lift bags. Different strokes for different folks.....)
NWGratefulDiver
May 14th, 2010, 05:25 PM
On my last dive trip to the Galapagos, one of my dive mates highly recommended getting an SMB with a spooled line instead of the mouth-inflatable safety sausage I had (the liveaboard recommended them for the trip -- I'd never had one before). He said that he oftened deployed the SMB at 15', when he did his safety stop.
I have to admit that his SMB looked quite cool, particularly since you could inflate it with your second stage. But I'm wondering why one would deploy an SMB while still underwater. Can someone please explain?
Thanks in advance.
A story to illustrate why ... a buddy and I were diving off an island in British Columbia. We reached a point where the current coming from the other side of the island met the current we were peacefully drifting along in ... and suddenly we found ourselves pulled out away from the island. The bottom dropped from the 75 fsw we were drifting at to who knows where ... it simply disappeared underneath us. The strength of the current was such that there was no chance of swimming against it to get back to where we could see anything but the water around us. My buddy immediately deployed an SMB and we began to ascend. Approximately six minutes later we surfaced ... we were a good quarter-mile from the island, but the dive boat was only about 30 feet from our SMB. The crew knew all the while where we were, and followed our progress as we ascended. Besides providing the crew a visual cue as to our whereabouts, the bag and line also gave us a visual cue as to our ascent rate, and an easy means to track our safety stop depth.
Wow that looks hard!:sarcasm: I bought one this season. Took it diving and deployed to try it out. Where does the training come in? Is there a PADI course for that?
I dunno about PADI, but I teach SMB deployment as part of my NAUI AOW class.
I particularly liked the point he made about not putting your finger to hold the reel because if the SMB gets caught up in something it could very well just break it!
The video is very good and thorough. Only one point I do differently ... which is that I do not take the double-ender off the spool until just before I inflate the bag. Think of the SMB like a grenade ... and the double-ender is the pin. You don't "pull the pin" until the grenade is ready to be launched. Otherwise, if for any reason you let go of the spool ... :shocked2:
... Bob (Grateful Diver)
knowone
May 14th, 2010, 07:38 PM
On my last dive trip to the Galapagos, one of my dive mates highly recommended getting an SMB with a spooled line instead of the mouth-inflatable safety sausage I had (the liveaboard recommended them for the trip -- I'd never had one before). He said that he oftened deployed the SMB at 15', when he did his safety stop.
I have to admit that his SMB looked quite cool, particularly since you could inflate it with your second stage. But I'm wondering why one would deploy an SMB while still underwater. Can someone please explain?
Thanks in advance.
Have someone that actually knows what they are talking about explain and deploy a couple with you.
RoatanMan
May 14th, 2010, 07:49 PM
If the boatsman is going to see an SMB, they will also see a sausage, which is lighter and cheaper. You can finger spool a sausage just the same as an SMB.
Boatsman like when you shoot it and hang at 15' awaiting a pickup. You stay safe and vomit-free, under the surge. When they decide it's your turn (they plan the best practical route), you''ll see the boat appear. Swim away from the reef towards the boat and make your ascent safely.
Whichever your choose, mark your device with distinctive Magik Marker- either big letters or design.
Show this design in advance to your boatsman in any congested area where different resorts might be looking for different people. Not so much an issue in the Galloping Pogos, but in the Red Sea, the Philippines and many other areas... it could really be helpful.
Either way- you can use the device to pass it to the boatsman from a safe distance- then he can reel you in by the cord if necessary.
I have a 4' safety sausage and a "porn-star sized SMB". I take the one that is most relevant for conditions and expertise of the boatsman. The guys in Ecuador are really eagle eyed.
k374
May 15th, 2010, 01:00 AM
question... how do these SMBs usually stay upright at the surface? I would think that they would just fall over when they hit the surface. What about if there are winds, will they tend to fall over?
Tortuga68
May 15th, 2010, 07:38 AM
question... how do these SMBs usually stay upright at the surface?
You're on the other end of the line... pull down
flw
May 15th, 2010, 09:22 AM
We use them on pretty much every boat dive, as do most other divers in Scotland. Most charters will require at the very minimum one dsmb per pair, possibly one per diver.
They are deployed at the end of every dive, if on a shallowinsh dive from the bottom, or on a deeper one from around 20-30m ideally. No boat will ever be moored, so the descent/ascent is done via a shot line - which as the tide starts to build may be unusable on the way back. With a significant deco requirement, then the additional stresses ( sliding up line issues) associated with hanging onto a line in a strong tide/current may be negated simply by putting up a line and going with the flow. As long as all divers do the same, they will end up drifting in a line, failry close together - unstressed and no line crowding issues - easy for the boat to cover - and since he will know your run-time anyway - the boat will be right there on surfacing
It's easier to inflate with one holding the reel, and a second diver filling with a second stage. However, although there's a definite knack to it, it's also easy enough to fill from your own exhauast bubbles, which whilst there is an entanglement danger, it is avoidable with care and it does mean it's easy to inflate mid water and solo - which in very tidal conditions even with buddy pairings may be necessary
Crush
May 15th, 2010, 09:43 AM
question... how do these SMBs usually stay upright at the surface? I would think that they would just fall over when they hit the surface. What about if there are winds, will they tend to fall over?
When ascending on a line/rescue sausage, I make sure that I am somewhat negatively buoyant. Hanging off the line keeps the rescue sausage vertical (as Tortuga68 mentioned).
deepdvr1
May 15th, 2010, 10:24 AM
GUE Fundamentals would be a good course to learn this skill.
D_B
May 15th, 2010, 10:53 AM
Seeing as this is in basic scuba I'll share what I thought was the most helpful thing I learned when I first did mine.
when you come to your stop and go to rig your SMB for deployment, don't look directly at it while doing so, do it "out of the corner of your eye" using your peripheral vision while looking at the particulate matter in the water, it provides direct and instant feed back to see if your rising or dropping while your "distracted" by your SMB .. made my depth holding much easier
One thing mentioned to us when doing it for the first time is to do it at the end of your safety stop , that way if you rise up during a not so perfect release, it's at the end anyway ... yeah, the very first time is a learning experience .. just remember this when you inflate it .. when it pulls, you let go, NOW! :blush:
Tortuga68
May 15th, 2010, 10:54 AM
It should be part of OW IMO but it's been dumbed down so much now you're lucky if they teach you how to put a reg in your mouth with some agencies
D_B
May 15th, 2010, 10:59 AM
I think that OW might be a bit early, I remember mine (3 weeks) and unless your taking a four week course , I think that would have been one thing too many for me .. I remember the stress of OW because .. it's all new, all so important, thinking my life depends on it
Crush
May 15th, 2010, 11:02 AM
dougchartier,
For the reasons mentioned by D_B and others, I find it easier to deploy a rescue sausage below 40 feet than at, say, at 20 feet. The deeper you are, the lesser the volume or air (at depth) you have to put into the rescue sausage to have it fully inflated at the surface (the air expands as it rises). This means that you will have to deal with a smaller buoyancy change at depth (owing to the rescue sausage trying to pull you up as you hold onto it to fill it). Having said that, I am not advocating that you first try to deploy your rescue sausage at a challenging depth.
D_B
May 15th, 2010, 11:08 AM
Mpetryk .. yes, my dive buddy that time was pufferfish and he would deploy his at 40 feet and told me the same thing as you when I complaned it was hard to get enough air in the SMB at 20 feet to have it fully inflated on the surface, without having it try to drag you upwards while filling it
Tortuga68
May 15th, 2010, 11:43 AM
I think that OW might be a bit early
I understand your point, but it's a valuable skill nonetheless
This means that you will have to deal with a smaller buoyancy change at depth
Lift is lift, regardless of depth
TSandM
May 15th, 2010, 12:32 PM
Lift is lift, regardless of depth
Um, actually, no. If that were true, nobody would ever have a runaway ascent. If you put one liter of air into something at 100 feet, at 30 feet you have two liters, and they displace two liters of water, and therefore create more lift.
It is easier to shoot a bag deeper for the reasons already given. You just have a huge amount of line to your spool to spool up or otherwise manage on the way to the surface.
One tip for those who are shooting bags in the shallows (safety stop). There is no need to spool up the line on ascent. You can get to the surface, and fairly rapidly do it there. (This doesn't work from 70 feet, though :) )
mpetryk, I'm not sure what distinction you are making between an SMB and a rescue sausage. I haven't seen the latter term before. To me, it's a DSMB if it can be deployed at depth, and a safety sausage if it is designed to be inflated on the surface. A DSMB can be used for a variety of things, including towing as a dive marker (not sure if it's a legal dive "flag" everywhere or not) or deploying at the end of the dive as a signal to the boat.
Tortuga68
May 15th, 2010, 01:31 PM
If you put one liter of air into something at 100 feet, at 30 feet you have two liters, and they displace two liters of water, and therefore create more lift
Yes but that's not what I was talking about - maybe I expressed it poorly, sorry
What I was trying to say is that lift is lift at the same depth, regardless of volume
The deeper you are, the lesser the volume or air (at depth) you have to put into the SMB to have it fully inflated at the surface (the air expands as it rises). This means that you will have to deal with a smaller buoyancy change at depth
This is the point I was trying to address
When you deploy your SMB, the lift generated will be related to the volume of air that you have put into it, regardless of the depth you deployed it at
As you said, once you let it go, the lift will increase as it ascends
But unless you **** up, that lift won't be applied to you
Either way, you won't have a "smaller buoyancy change" to deal with at depth
TSandM
May 15th, 2010, 01:39 PM
Tortuga, I'm confused. 100 fsw is 4ATA, right? 30 fsw is 2 ATA, right? So the one liter you put in at 100 fsw becomes 2 liters at 30, because you have half the pressure, so twice the volume? I don't think I have this screwed up :)
So, if you want the SMB taut and full at the surface, you can fill it one quarter full at 100 fsw. If it holds, say, two liters of gas, you can put in 500 ccs at 100 fsw. That gives you the equivalent of 500 ccs of lift to manage. Obviously, the bag will expand on the way up, but at that point, you are allowing the line to unspool without hindrance, so it doesn't matter to your stability where you are.
On the other hand, if you want the bag completely full at the surface, you have to fill it half full at 30 fsw. You've now displaced twice as much water, which makes the bag, prior to you releasing it, twice as buoyant and more difficult to manage (especially since your own buoyancy is more delicate that shallow). Again, what happens after you let go of it is irrelevant.
It is easier to stay completely stable during a bag shoot, when you are new to it, if you do it deeper; on the other hand, it's much more dangerous to lose control of your buoyancy or get caught in the line if you shoot the bag deep when you aren't accustomed to doing it. For me, the bottom line is to put up with the instability in the shallows -- and having to deal with it will very soon teach you how to shoot a bag efficiently and quickly, so you don't get unstable.
Crush
May 15th, 2010, 01:42 PM
dougchartier,
For the reasons mentioned by D_B and others, I find it easier to deploy a rescue sausage below 40 feet than at, say, at 20 feet. The deeper you are, the lesser the volume or air (at depth) you have to put into the SMB to have it fully inflated at the surface (the air expands as it rises). This means that you will have to deal with a smaller buoyancy change at depth (owing to the rescue sausage trying to pull you up as you hold onto it to fill it). Having said that, I am not advocating that you first try to deploy your rescue sausage at a challenging depth.
Tortuga68, TSandM,
Perhaps I was unclear in my wording. An example to illustrate: let's take a rescue sausage with 20 lbs of lift.
Deploying said rescue sausage at approx. 30 feet will allow you to fill the rescue sausage to half its capacity at that depth. As it rises the air will expand. Thus, at the moment of release at 30 feet the half filled rescue sausage is buoyant by half of its capacity, or 10 lbs.
Deploying said rescue sausage at approx. 60 feet will allow you to fill the rescue sausage to one-third of its capacity at that depth. At the moment of release at 60 feet the one-third filled rescue sausage is buoyant by one-third of its capacity, or about 6.7 lbs.
Deploying said rescue sausage at approx. 90 feet will allow you to fill the rescue sausage to one-quarter of its capacity at that depth. At the moment of release at 90 feet the one-quarter filled rescue sausage is buoyant by one-quarter of its capacity, or about 5 lbs.
In all cases the rescue sausage will reach its full lift capacity of 20 lbs at the surface. This is not to say that you could not fill the rescue sausage to capacity at depth, and in such case, it's lift would be a constant 20 lbs as it ascends and vents.
Crush
May 15th, 2010, 01:47 PM
mpetryk, I'm not sure what distinction you are making between an SMB and a rescue sausage. I haven't seen the latter term before. To me, it's a DSMB if it can be deployed at depth, and a safety sausage if it is designed to be inflated on the surface. A DSMB can be used for a variety of things, including towing as a dive marker (not sure if it's a legal dive "flag" everywhere or not) or deploying at the end of the dive as a signal to the boat.
TSandM,
You are perfectly correct. In an earlier post in this thread I correctly defined SMB and rescue sausage. I have since gone on to use the term SMB incorrectly - my bad. I will be re-editing my posts now to clear this up.
To me a rescue sausage is a DSMB - is my usage of the term incorrect?
Thanks!
Tortuga68
May 15th, 2010, 01:49 PM
Tortuga, I'm confused. 100 fsw is 4ATA, right? 30 fsw is 2 ATA, right? So the one liter you put in at 100 fsw becomes 2 liters at 30, because you have half the pressure, so twice the volume?
Sorry Lynne & mpetryk, I have a bad habit of posting then editing as I decide what it was I actually meant to say
Especially at 03:50am :)
I think there was some confusion over whether we were talking about the buoyancy of the SMB or the diver
Anyway, I think we all agree on the principles as stated
Crush
May 15th, 2010, 01:57 PM
But unless you **** up, that lift won't be applied to you
Either way, you won't have a "smaller buoyancy change" to deal with at depth
I am confused - perhaps I am using my rescue sausage/DSMB the wrong way. If I fill the 20# rescue sausage to 1/4 of its capacity at 90 feet, at the instant before I let go of it, it is pulling me up with 5# lift. Once I let go, that force is no longer acting upon me. However, at the moment before release there was a buoyancy change. If the fill and release are done quickly, the change in buoyancy may have only a negligible effect on my depth.
Oops - I stated typing before I saw your response, Tortuga68. It is all good. :)
TSandM
May 15th, 2010, 02:10 PM
I'm still confused. A deployable surface marker buoy (DSMB, or as commonly used, SMB) is a device designed to be inflated either underwater or on the surface. It is commonly attached to a spool, and deployed at the end of the dive as a marker for the boat or others. Some people tow one as a dive flag (I do not know if this meets the dive flag requirements in all locations). An SMB can be designed to be orally inflated, inflated with a low pressure hose, or inflated with a purged regulator. They come in a variety of sizes -- lengths, widths, and amounts of lift. Some have OPVs and others do not.
There ARE open-ended tubes which are only designed to be inflated and waved at the surface. They have no mechanism for attaching them to a spool or reel. They are almost always just open-ended. I've seen this type of thing referred to as a "safety sausage".
It's the difference between your SMB and your "rescue sausage" that has me stumped. What would one see as the design differences between the two, or are you simply using two different terms to distinguish the intended PURPOSE of the same device?
Tortuga68
May 15th, 2010, 02:13 PM
NP mpetryk
On deep dives I will brake the reel and use the SMB to help me ascend to the first stop, at the appropriate rate
As someone said earlier, it's nice for the boat crew to see the balloons pop and know we are ok
Tortuga68
May 15th, 2010, 02:19 PM
It's the difference between your SMB and your "rescue sausage" that has me stumped. What would one see as the design differences between the two, or are you simply using two different terms to distinguish the intended PURPOSE of the same device?
There are so many different terms used here on SB, but I think in most cases they mean the same thing. I mostly call them an SMB here (even though I nearly always use mine as a DSMB), but balloon, blob, sausage etc are pretty common
But yes it can be confusing
Crush
May 15th, 2010, 07:18 PM
I'm still confused.
TSandM, it is likely me who is confused.
This is what I referred to as a rescue sausage:
click here (http://www.leisurepro.com/Prod/CategoryID_1105/Context_965/Sort_Stock/DescSort_0/OMSLB5.html?Hit=1)
However, it now seems that everyone but me calls this a surface marker buoy. Since it resembles a sausage to me, I will continue to refer to it as such in my head. However, to minimize confusion, I will now refer to it publicly as an SMB.
