difficulty with safety stop

[TSandM]

If you are already having problems holding a stop, I would NOT recommend getting and trying to manage an SMB during your ascent. Although it does give you a point of reference, shooting a bag is significant task loading, and if your buoyancy control is shaky, adding that distraction will make it much worse.

I had horrible problems learning to hold a stop -- I was on my 50th dive before I managed it. I would recommend learning to ascend in a horizontal position, because you're more stable that way. Don't ever get too far off neutral -- inhale, wait to begin to rise, then exhale and see if you stop, and if you don't, VENT. Watch your gauge. If your gauge is on a console, pull it out and hold it in front of you. If it's on your wrist, it's easier. Pay very close attention to your ears and how your gear feels, to warn you when you are getting light. One thing Joe Talavera taught me is that there is a very small window where you can control your buoyancy with your breath; if you get farther from your desired depth than that, you have to use your BC or dry suit for control. So noticing variations from your desired depth quickly and correcting them early is key.

If you are vertical, any finning you do will drive you upwards, so if you choose to ascend in that position, remember that if you are going up too fast, you need to stop kicking.

Remember that your buddy is a visual reference as well. If you get a chance to dive with someone who has good buoyancy control and can hold his stops, that will help a lot.

Good luck with this -- It IS learnable. And people to whom it comes easily will not understand why you are having trouble, but I do.

 

[Jim Lapenta]

The bag would be a new skill. That makes total sense. The bag has the line,correct?

Yes a line is attached to the bag. But as TS&M says it can be a difficult skill to master if your buoyancy is still in the developing stage. How deep were the dives you are doing. It is easier to control buoyancy a little deeper than shallow since the pressure changes are not as radical. I like to do early dry suit skills in open water at 50 ft then move up to shallower depths. Takes more time but it makes for a more forgiving experience. But as I said with some instruction and practice shooting a bag makes for nice ascents. I like to use a 50 ft reel and my diverite 50lb bag. At first it was a little unnerving. But as I went on with it it helped to develop my skills as related to holding stops. I had not much difficulty anyway but having a visual and tactile reference let me really fine tune it. I have my line knotted at 5 ft intervals with two knots at 20 and three at 15. I can now know for a fact when I'm getting a little light or heavy. Usually it's right on but those times when vis is bad it's very useful. I could do a blackwater ascent, not be able to see my guage, and know where I am.

 

[gcbryan]

Make sure you are weighted properly so that you know it's possible to hold a stop and then err on the side of negative buoyancy so that if you've made a mistake you will slowly start to sink rather than rise. The rising will soon get out of hand as a newer diver. You will be able to handle being a little negative.

The goal of course is to be neutral and stable in the water column. Make small movements rather than going vertically abruptly. Do your stop horizontally even if you don't ascend horizontally. If you have the chance to learn to ascend horizontally that would be a big help as well.

 

[DA Aquamaster]

get rid of ALL the air in your BC before ascending.......also, if you're @ the end of your air supply, you'll be a little liter than the beginning so you may need a little more weight to compensate for this.....

Sorry...I encounter victims of that advice all the time. Dumping all the gas from the BC before ascending just removes the diver from even the general vicinity of neutral bouyancy and forces them to swim up, creating silt and general destruction on the bottom and, if they are over weighted, greatly tiring the diver before he or she gets to the safety stop depth.

More importantly, over the long term reliance on fins for buoyancy control creates divers that fin constantly and often unconsciously to maintain buoyancy and it greatly complicates the even prevents the mastery of good buoyancy skills. Diving is not about swimming it is about floating at neutral bouyancy at your chosen depths, so stop swimming and start floating.

The diver should start the ascent neutral and then dump air in small amounts as needed to maintain neutral bouyancy. New divers will usually ascend vertically and when doing that the diver can watch the smallest of their exhaled bubbles and ascend at the same rate they do. Keep switching to smaller bubbles as they get bigger as they go up, and keep dumping air as needed not to pass them. Dumping a bit too much is fine as a couple fin kicks will keep you going in the right direction.

The secret to hitting a 15 ft stop is to plan and make a pause at 30'. Any stops between 30' and 10' are fine in terms of safety stops, but they get harder to hold as you get shallower as the rate of change in buoyancy per foot is much greater. Plus planning to stop at 30 ft makes you slow down and ensures you will not be so buoyant that you blow right through it. Once you get neutral at 30', come up slowly and carefully maintaining netrual buoyancy or staying a half pound or so negative and finning up very gently with an occassional very slight kick. A nice slow ascent with small dumps, and if needed very small additions and no huge buoyancy changes - again watching your smallest bubbles to gauge your ascent. Also, even in 100' viz there are small particles suspended in the water that you can watch to hold a constant depth if you look for them.

-----

Ease of buoyancy control starts with proper weighting. A diver should be neutral at 15' with no air in the BC, no finning and normal (average) lung volume with 500 psi left in the tank.

In my experience if a diver can float vertically at eyeball level at the surface with full lungs (with all the above conditions met) and then sink when he or she exhales, they will be very close to neutral at 15' with average lung volume. So when you are new, in a different configuration or in a different exposure suit, do a buoyancy check at the end of the dive to see where you are at in this regard and add or subtract weight as needed.

Be absolutely sure you are not finning and hold your fins or cross your legs if needed to ensure you are not, as finning creates the perception you need more weight and if you are overweighted, the larger air volume needed in the BC is much harder to manage - especially at shallow safety stop depths.

In my experience, the vast majority of new divers are badly overweighted by instructors "helping" them get down rather than working with them on proper buoyancy and eliminating anxiety related or buoyancy compensating fin kicking. It is not unusual to have to take 10 or even 20 pounds of lead off a new diver. There are quite simply too many instructors who are not very good or don't take the time to teach decent buoyancy skills in today's often very abbreviated classes.

A few more thoughts:

1. The average person has 4 to 5 pounds of buoyancy shift from full to empty lungs. That is a very powerful and useful buoyancy control device, but it also means you are never truly neutral (at least on open circuit scuba) but will instead rise and fall slowly as you inhale and exhale. Learning to feel for that and to understnad the slight lag due to inertia will help you understand and master good buoyancy control.

2. An AL 80 (or any other tank with about 80 cu ft of gas) will have about 5 lbs of buoyancy shift as it goes from full to empty, so you will be about 5 lbs heavy at the start of a dive. That requires extra gas volume in the BC that is not much more work at depth but is harder to manage at shallow depths. However the reverse is also true so buoyancy should actually get easier as the dive progresses if you are properly weighted. It also means that you can weight yourself to float at eyeball level at the surface with full lungs, no gas in the BC and a full tank. You can then just add 4 to 5 lbs of weight and be very close to neutral at the end of a dive with a near empty tank.

3. Ignore the ascent rate indicator on your computer. It has a lag due to the sampling rate, which when combined with the shift in buyancy due to breathing and the lag due to inertia makes it a very non precision instrument. If you depend completely on it's advice on a precision ascent above 30', you will fail miserably every time. Environmental cues will serve you much better and overtime time you will develop a "feel" for whether you are ascending, decending or neutral.

 

[diver 85]

Sorry...I encounter victims of that advice all the time. Dumping all the gas from the BC before ascending just removes the diver from even the general vicinity of neutral bouyancy and forces them to swim up, creating silt and general destruction on the bottom and, if they are over weighted, greatly tiring the diver before he or she gets to the safety stop depth.

More importantly, over the long term reliance on fins for buoyancy control creates divers that fin constantly and often unconsciously to maintain buoyancy and it greatly complicates the even prevents the mastery of good buoyancy skills. Diving is not about swimming it is about floating at neutral bouyancy at your chosen depths, so stop swimming and start floating.

The diver should start the ascent neutral and then dump air in small amounts as needed to maintain neutral bouyancy. New divers will usually ascend vertically and when doing that the diver can watch the smallest of their exhaled bubbles and ascend at the same rate they do. Keep switching to smaller bubbles as they get bigger as they go up, and keep dumping air as needed not to pass them. Dumping a bit too much is fine as a couple fin kicks will keep you going in the right direction.

The secret to hitting a 15 ft stop is to plan and make a pause at 30'. Any stops between 30' and 10' are fine in terms of safety stops, but they get harder to hold as you get shallower as the rate of change in buoyancy per foot is much greater. Plus planning to stop at 30 ft makes you slow down and ensures you will not be so buoyant that you blow right through it. Once you get neutral at 30', come up slowly and carefully maintaining netrual buoyancy or staying a half pound or so negative and finning up very gently with an occassional very slight kick. A nice slow ascent with small dumps, and if needed very small additions and no huge buoyancy changes - again watching your smallest bubbles to gauge your ascent. Also, even in 100' viz there are small particles suspended in the water that you can watch to hold a constant depth if you look for them.

-----

Ease of buoyancy control starts with proper weighting. A diver should be neutral at 15' with no air in the BC, no finning and normal (average) lung volume with 500 psi left in the tank.

In my experience if a diver can float vertically at eyeball level at the surface with full lungs (with all the above conditions met) and then sink when he or she exhales, they will be very close to neutral at 15' with average lung volume. So when you are new, in a different configuration or in a different exposure suit, do a buoyancy check at the end of the dive to see where you are at in this regard and add or subtract weight as needed.

Be absolutely sure you are not finning and hold your fins or cross your legs if needed to ensure you are not, as finning creates the perception you need more weight and if you are overweighted, the larger air volume needed in the BC is much harder to manage - especially at shallow safety stop depths.

In my experience, the vast majority of new divers are badly overweighted by instructors "helping" them get down rather than working with them on proper buoyancy and eliminating anxiety related or buoyancy compensating fin kicking. It is not unusual to have to take 10 or even 20 pounds of lead off a new diver. There are quite simply too many instructors who are not very good or don't take the time to teach decent buoyancy skills in today's often very abbreviated classes.

A few more thoughts:

1. The average person has 4 to 5 pounds of buoyancy shift from full to empty lungs. That is a very powerful and useful buoyancy control device, but it also means you are never truly neutral (at least on open circuit scuba) but will instead rise and fall slowly as you inhale and exhale. Learning to feel for that and to understnad the slight lag due to inertia will help you understand and master good buoyancy control.

2. An AL 80 (or any other tank with about 80 cu ft of gas) will have about 5 lbs of buoyancy shift as it goes from full to empty, so you will be about 5 lbs heavy at the start of a dive. That requires extra gas volume in the BC that is not much more work at depth but is harder to manage at shallow depths. However the reverse is also true so buoyancy should actually get easier as the dive progresses if you are properly weighted. It also means that you can weight yourself to float at eyeball level at the surface with full lungs, no gas in the BC and a full tank. You can then just add 4 to 5 lbs of weight and be very close to neutral at the end of a dive with a near empty tank.

3. Ignore the ascent rate indicator on your computer. It has a lag due to the sampling rate, which when combined with the shift in buyancy due to breathing and the lag due to inertia makes it a very non precision instrument. If you depend completely on it's advice on a precision ascent above 30', you will fail miserably every time. Environmental cues will serve you much better and overtime time you will develop a "feel" for whether you are ascending, decending or neutral.

Sorry......well-guess I was trained incorrectly.......I was assuming he's properly weighted--something else I was trained to be from the beginning....guess I was either taught correctly, from the beginning--looks like something you don't do--or I got lucky about 1200 dives ago.....

We always say on the golf course 'I'd rather be lucky than good'----guess that holds true for being UW........

So, in review, I was taught(1985---pre computers or one's that were worth a ****), kill your running time ie BT, dump your air & start upward.......NEVER had-- nor my wife & 14 YO daughter then, & within 4 yrs 2 12 YO sons--problems with hitting 15' & holding it....Maybe between the 5 of us & our instructor(all the same guy) we just were/are better divers....Who knows.............................lol


This isn't rocket surgery----so don't make it out to be, any fool knows you're not going to stop on a dime while moving(think physics, btw, I've had 11 courses in my life- 8 of them post graduate)---from cars to helicopters to space shuttles to moving in the water.If someone doesn't realize this, maybe tiddly winks needs to be their forte.....I've come to find, people really try to make this sport alot harder than it is, once you have the ground rules downs...........Use your head & you'll be alot better off, it's called COMMON SENSE -----again advice to be used in almost every facet of life, including donning common everyday shoes.........a 16 page dissertation on leaving the bottom???.......give me a break..........

Oh, have a great day.............rotflmao........

 

[dumpsterDiver]

DA is completely correct. MAking a general statement to dump all air froma BC BEFORE ascending is very poor advice. If the diver is wearing a thick suit, it is quite possible that the BC has 20 or more lbs of air in it at depth. AS DA tried to explain, there is absolutely no reason to force the diver to make a strenous swimming ascent, when the BC will allow an effortless trip to the surface.

For myself, I maintain a very slight positive bouyancy in my BC (on ascent) and use each inhalation as a step to float up a foot or so (as TSM describes) and upon exhalation (you stop)and the tiny particles in the water which appear stationary provide visual confirmation that you have stopped. If you are moving up after exhalation, then dump a little air. This is what I call ADVANCED bouyancy control for ascent.

For open water students, I taught a slightly different method. They were to maintain the slightest degree of negative bouyancy and offset it by VERY gently licking up. To test if their bouyancy was correct, they stop kicking and they should stop or just start to sink slowly. Gradually they learn to kick less and less (and more gently) and eventually use lung volume to ascend with essentially no kicking. Having the new diver strive to maintain the slightest negative bouyancy while ascending is a little safer and provides a little margin for error that a perfectly neutral (or slightly) positive ascent does not provide.

However, I NEVER told them to dump ALL the air from their BC before an ascent!

 

[DandyDon]

Practice practice practice...

The bag would be a new skill. That makes total sense. The bag has the line,correct?

Not the right answer for your problem, but was enough was said. Next thing that would happen is your buddy untangling you from the slack line. I had to do that for mine while holding mine tight; we no longer shoot lines on the same dive.

I'm assuming that what you are saying is that it's difficult to maintain 15' because you have no point of reference. You are diving well within NDL's so don't get so hung up on this optional safety stop. It's a great time to practice and improve your buoyancy skills. (unless ofcourse, you happen to be underweighted) Keep an eye on your depth gauge as you adjust the amount of air in your BC in SMALL increments. Wait atleast 2 seconds between your adjustments.

I'm not that great at explaining things so I hope I haven't confused you. Someone else will chime in and explain better, I'm sure.

You explained it well. That's all there is to it. And I prefer dump valve to release valve to avoid confusion. Have seen too many times divers added air by mistake at 20 ft, then did the cork act to the surface. :shocked2:

In addition to the above recommendatios, try holding the stop deeper. Remember, the safety stop is optional within NDL, and is really just a way to control (i.e., SLOOOW DOWN) your final ascent.

Try holding the stop closer to 20', then a very slow ascent from there.

Best wishes.

Goooooooooood idea.

 

[don Francisco]

It's a bouyancy control thing and needs to be practiced, especially because your bouyancy becomes more dynamic at shallower depths.

Here's a few things that'll help.

1- as you ascend stop and level off every 10 feet, establishing and confirming neutral bouyancy. Hold that depth until your comfortable with it before ascending to the next 10' level. This serves two purposes, it assures that you won't be too far off neutral bouyancy as you rise, and it slows you down so momentum won't carry you beyond your planned stop depth.

2- begin your safety stop at 20', where it's slightly easier to hover than shallower. Double check that your BC is totally empty, by hunching your shoulder and getting that last drop of air out.

This is also an opportunity to do a proper weight check. With an empty tank (500psi or so) you should be marginally heavy with 1/2 full lungs, and rise slightly on inhales and sink slightly on exhales. (remember practicing bouyancy in your OW class?) If you're slightly light don't go higher, finish your safety stop at 20' and add a pound on your next dive.

3- After mastering bouyancy at 20' ease up to the 15' depth, and remember to maintain bouyancy with breathing. Inhale as you sink, exhale on the rise, so that your using your lungs to counter bouyancy changes.

Other do's and don'ts.

Do safety stops horizontal because that slows vertical motion in the water. You can also swim up or down at a shallow planing angle to maintain depth if you need to. If you're vertical and light you have no easy method for resisting upwards motion.

Use a fixed reference like a shallow coral head, or an analog depth gauge to help maintain depth. If there's someone hanging from a line in calm water watch him, otherwise do not watch other divers who might be rising and falling. Adjusting to moving targets makes maintining your depth doubly difficult.

Make sure to control any unconcious finning. I see many divers struggling to hover, even when overweighted because they're vertical and have happy feet, which are propelling them upwards.

Lastly relax and be confident that using the techniques above, you'll be able to hold your stop forever if you need to. Nothing screws up a free safety stop worse than being nervous about it. Once you tense up, you'll retain air and float upwards, then you'll struggle which makes you retain even more air and next thing you know you pop to the surface.

To summarize, the secret to safety stops is having bouyancy truly under control, no unconsious finning, and being totally relaxed.

 

[Web Monkey]

Did my first drift dive off a boat last week in Florida (had done one other in a river). Did two dives and both times had difficulty with my safety stop. I was well within ND limits but it did not make me comfortable and frustrated me. Most of my dives have been wreck dives in NJ with a line to hold onto when making a safety stop. In Florida I went up slow but had difficulty holding a safety stop without something to hold to. Any tips?

Everybody else tossed in their 2 cents, so I will too.

You might want to do a buoyancy check with an almost empty tank (as described in your OW book) and make sure your that you're weighted correctly.

If you're under-weighted, holding a safety stop will be impossible, and if you're significantly overweighted, it will be extremely difficult. Also, there's nothing magic about 15'. If there's a lot of surge at 15', 20' is just fine and may be easier. In either case, just make sure that your final ascent to the surface is nice and slow. Taking 2 minutes to cover the last 20' would be great, and your body will thank you for it.

Terry

 

[diver 85]

DA is completely correct. MAking a general statement to dump all air froma BC BEFORE ascending is very poor advice. If the diver is wearing a thick suit, it is quite possible that the BC has 20 or more lbs of air in it at depth. AS DA tried to explain, there is absolutely no reason to force the diver to make a strenous swimming ascent, when the BC will allow an effortless trip to the surface.

For myself, I maintain a very slight positive bouyancy in my BC (on ascent) and use each inhalation as a step to float up a foot or so (as TSM describes) and upon exhalation (you stop)and the tiny particles in the water which appear stationary provide visual confirmation that you have stopped. If you are moving up after exhalation, then dump a little air. This is what I call ADVANCED bouyancy control for ascent.

For open water students, I taught a slightly different method. They were to maintain the slightest degree of negative bouyancy and offset it by VERY gently licking up. To test if their bouyancy was correct, they stop kicking and they should stop or just start ti sink slowly. Gradually they learn to kick less and less (and more gently) and eventually use lung volume to ascend with essentially no kicking. Having the new diver strive to maintain the slightest negative bouyancy while ascending is a little safer and provides a little margin for error that a perfectly neutral (or slightly) positive ascent does not provide.

However, I NEVER told them to dump ALL the air from their BC before an ascent!

and how many new divers " maintain the slightest degree of negative bouyancy"....lol.........I guess that comes on OW check out dive 3---or is it 4??.....You are speaking of a perfect world & in diving I'm guessing that comes somewhere after dive 1 and number 500.....lol, a new diver with perfect skills.....some of you people here are a hoot....

Out of curiosity, when did you acheive this level of perfection??, just curious......