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Any experts out there have experience in dealing with a buddy who is either starting to invert in his dry suit or more severely, a buddy who has inverted and is possibly making an uncontrolled ascent to the surface.
I found myself in this position last week with a novice diver. Luckily I managed to grab him before he fully inverted, and "corrected" his position thus preventing what might have been an unpleasant experience.
Stewart
DL/ADI
Nigel Hewitt
13-04-2006, 14:45
I found myself in this position last week with a novice diver. Luckily I managed to grab him before he fully inverted, and "corrected" his position thus preventing what might have been an unpleasant experience.But surely the tuck-and-somersault is in Drysuit 101....
This is what happens if people insist on using the suit for buoyancy.
This is what happens if people insist on using the suit for buoyancy.
See slide 2.4 in the drysuit SDC instructor Notes
http://www.bsac.org/techserv/irc/drysuitinstructornotes2001.pdf
;)
using the suit for buoyancy is not the issue, it's incorrect weighting that causes the problem, But essencially it will always be down to persional preference, But propper training is key to safe dry suit diving.
Ta Ta
David Walker
13-04-2006, 15:13
I'd suggest that the first aim should be treating the problem at its source - make sure your buddy gets some additional training to ensure they can dive safely in their own suit. They should be able to deal with simple bouyancy themself, rather than needing you to help them, so definitely recommend that your buddy gets some help from an instructor to find out why they're having these problems in the first place. Even if they do get inverted, they should be able to get out of it themself - its a fairly simple thing to do.
In terms of helping them, if necessary (and I wouldn't recommend it if you're inexperienced yourself), you need to catch them early. Mostly it will mean that you just hold onto them, make sure they don't get pulled up my their feet, and if there's anything around to hold onto then make sure they can reach that and grab if until they're sorted. Like I said though, they need to know how to get out of the inversion themself, and it is far far better to treat that than to teach yourself how to deal with what instructors have to do during training.
The problem you will find in doing anything beyond that is that you simply get pulled up with them if they start ascending. If you're weighted correctly you will not be able to do anything significant to slow an ascent down, and then you risk two casulaties instead of one if its a fast ascent from depth. Just follow them as quickly as safely possible to make sure they are ok on the surface. What you will find instructors do is often dive overweighted, so that they've got extra air they can dump very quickly should they have to grab hold of a student ascending quickly, through drysuit trouble or anything else. I wouldn't recommend you try though though, as the extra air you will need to compensate could simply mean that you end up having the same problems as your buddy.
Its not easy, but if its happening regularly then I really would suggest that your buddy gets more help to find the cause, rather than you trying to learn how to fix it after its happened.
David
This is what happens if people insist on using the suit for buoyancy.
Mr Hewitt! Are you trying to cause a fight? Shame on you! :)
DS for buoyancy, cuff dumps, ankle weights rule!!!! http://www.springfield-shopper.de/Main/Smilies/5.gif
:)
Oops, am I allowed to a) post in here and, if so, b) post frivolity?
Proper Training for the buddy is key, and for the record I agree with Nigel. I learnt the hardway as I used to use the suit for bouyance, no way I am doing that any more, personnally I just think it's stupid especially in my twin 12's.
Dry Suit to keep warm
BC for funny enough bouyance.
:)
Mark
If you look at the BSAC safe diving practices, it also states that when a drysuit is used the suit is to be used to control bouyancy underwater, & the BC is to be used for surface bouyancy only.
Nine times out of ten if someone has bouyancy problems (,& that includes inversions,) when using a drysuit, it is because they have far to much lead!
I know this issue cause's heated debate.
Generally I am happy to let people use the technique they prefer. However having seen the adverse side of multiple bouyancy compartments & the confusion/trouble they can cause (loss of bowel control, helicopter rides & long periods of time in pressureised steel tubes). I am now far more nervous about diving with a buddy, using the BC underwater & the drysuit than I used to be!
Gareth
I used to use the suit for bouyance
I still do. It makes a whole lot of sense unless you're carrying enormous quantities of gas.
no way I am doing that any more,personnally I just think it's stupid especially in my twin 12's.
Twin 12s are probably about the limit of what I'd do on my suit; particularly as my stages are extraordinarily heavy...
Dry Suit to keep warm
A whole load of Navy divers would disagree with you there.
BC for funny enough bouyance.
Why make hard-and-fast rules just by the name someone's ascribed to a piece of kit? Do you go round stabbing people that wear a stab jacket?
The bottom line is : what works, works. Using a suit for buoyancy works in most situations where the diver is not overweighted. Sadly, it seems that most divers are hugely overweighted. This means they cannot safely use the suit for buoyancy, and instead resort to ever-larger wings.
A better solution IMHO would be to sort out the weighting properly first. Then it becomes a decision based on what you're doing, not an imposition based on whether or not you can move.
Vic.
Twin 12s are probably about the limit of what I'd do on my suit; particularly as my stages are extraordinarily heavy...
I would personally not like to compensate for the whole stone of gas in a pair of full 12's using suit alone. You end up with a bubble behind your head which is a PITA and if something goes wrong, it's tricky to dump all of that air through your teeny weeny dump valve.
David Walker
13-04-2006, 17:33
This whole drysuit vs BC for bouyancy thing really is just a misunderstood argument as far as I can see.
I would say that my view is to use the drysuit for comfort, and the BC for anything else. However (and this is the bit that is often forgotten), if I am weighted correctly and am using a single cylinder then chances are the comfort level in my drysuit will be all the bouyancy I need... so in those circumstances you *could* say that i'm using the drysuit for bouyancy.
As far as I see it, this way I am flexible and considering all the air spaces all the time. Although I think my BC may be empty, it never is - EVER! So if you're using your drysuit, and focused on only using your drysuit, its easy to have that bit of air in your BC get the better of you and cause problems.
I look at this way as the most flexible - i'm not going to use the BC if I don't need it, but equally i'm not going to blindly ignore the fact that i've got 3 times as much air in my suit at the start of the dive than I need to keep me warm, and will use the BC if it is appropriate. As i'm used to using the BC, I can happily use either without any thought at all, as i'm ascending I tend to dump the BC occasionally in case any air is in there, and all works well.
Ultimately, the difference isn't that great - I think the only difference between the two is that some people refuse to use their BC at all underwater (other than in an emergency), while others are flexible and use whichever is more appropriate... which on large cylinders where you use a lot of air will generally mean your BC will contain air for much of the dive.
Obviously people are free to do either, i'm just trying to highlight the practical differences between the two methods (as I see it).
David
I would personally not like to compensate for the whole stone of gas in a pair of full 12's using suit alone.
I've done it. It wasn't so bad. I probably wouldn't deliberately do it again if I were still diving twin 12s.
You end up with a bubble behind your head which is a PITA[/QUOTE
Depends - my undersuit seems to lap it up quite nicely.
[QUOTE=Woz]and if something goes wrong, it's tricky to dump all of that air through your teeny weeny dump valve.
Disagree there - the problem is in keeping it *in*, should you decide to adopt strange and wonderful positions in the water.
The dump rate thang is only a problem once you've let your buoyancy get away from you by a long, long way...
Vic.
David
In principle I agree, I would use the BC in preference to being blown up like a mitchulan man. In fact I have in the past.
If we remove those that are using twin 12's with 12l stages, & return to the majority of divers, whose configuration is not going to weigh more than twin 10's & a stage.
i.e. 12l, 12l+3l, 15l, 15l+3l. 2x10l +3l, 2x10l +7l.
You 'should' be able to dive safely & comfortably using just the drysuit.
i.e. enough air to remove the squeeze should make you neutrally bouyant.
The problem I regularly see, is that there are those using the BC as well as the drysuit - because they need lots of air to make them neutrally bouyant.
When you look closely it is because they are carrying far to much weight in the first place. So rather than address the fundimental problem - too much lead, they address the symptom - & use the BC.
If we taught correct weighting & being neutral bouyant, correctly, far fewer people would be using BC's for bouyancy, because there is just no need!
I seem to spend most of my time on Advanced Nitrox courses attempting to remove huge amount of excess lead from candidates. Why does any one on a single 12l +3l in a membrane drysuit need 10kg of lead???
Whats even more frustrating, is having proved they don't need all that lead they promptly put it back on when they leave & teach the same poor practice to those they dive with!
Aghhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Gareth
Any experts out there have experience in dealing with a buddy who is either starting to invert in his dry suitKeep your arm straight and sweep down firmly at 90 degrees across your buddy's calfs. It should pivot them upright so their dumps are in the right position to work..
or more severely, a buddy who has inverted and is possibly making an uncontrolled ascent to the surface.Find a suitable attachment point low down on the BC (D-Ring), hang on tight, breathe out as hard as you can, dump all your own buoyancy. This may check the ascent long enough to right the buddy and/or dump his buoyancy. If you are still ascending make like a star-fish spreading arms and legs and keeping your fins horizontal. The idea is to create as much drag as possible and slow the ascent as much as possible. It is a pretty effective technique but it's up to you to decide when to let go. Be careful with your hands, try to avoid knocking your buddys DV out.
I found myself in this position last week with a novice diver. Luckily I managed to grab him before he fully inverted, and "corrected" his position thus preventing what might have been an unpleasant experience.Well done for sorting it out. Inverts and rapids are a fairly normal part of learning to dive.
As the others have said, prevention is better than cure.
If there is ANY doubt over a new divers ability to control buoyancy confine them to shallow water (< 6m). This will make things more difficult for them due to the expansion characteristics but they will learn faster and an uncontrolled or rapid will be far less traumatic.
Cast your eye over your novice buddies weightbelt. If it looks too heavy it probably is - do a buoyancy check with the emphasis on teaching a relaxed descent technique. INSIST that your novices do decent buoyancy checks regularly. Create the opportunity to perform one whenever you can. You should also teach them to do their own buoyancy checks.
Whether your buddy chooses to use their suit or BC is immaterial. Obviously you should encourage them to explore different buoyancy control techniques but the emphasis is what works for them and not what works for other people. They must be able to control buoyancy and until they can the only safe option is to keep them shallow so that a buoyancy problem is less likely to hurt them or you.
HTH
Thus far I have only used twin 10s and an alu 3 (my pony bottle) for 80%. I have managed fine just using my suit for buoyancy during the dive.
The one thing I will say is that I def want a fair bit of air in the dry suit on ascent as, without it, I get cold.
Now I have twin 12s and a.n.other cyllinder (yet to be acquired) I am hoping to still use my DS for dive buoyancy.
Also, I have never EVER (apart from training) come close to having a problem being inverted ............ mind you, all my diving is on wrecks so there is nothing sub 20 mtrs so I am not in the "tricky 10 mtrs" doing anything but deco/safety stops.
If you look at the BSAC safe diving practices, it also states that when a drysuit is used the suit is to be used to control bouyancy underwater, & the BC is to be used for surface bouyancy only.
Gareth
Good job that an awful lot of us ignore that bit then :)
If I have a boot squeeze I invert and let air go to my feet. With no dumps
anywhere, the only way to get rid of air is to go right way up again and
reverse the process.
So if I keep the ammount of air in the suit to a minimum, if I invert less will
go to my feet. That means suit for warmth/squeeze only.
No matter what the argument for and against using BC/Suit etc. in the early
days it is far better to use BC for bouyancy and suit for warmth, no
question.
T.
No matter what the argument for and against using BC/Suit etc. in the early days it is far better to use BC for bouyancy and suit for warmth, no
question.
Completely disagree.
In the early days, it's better to minimise the number of buoyancy sources a trainee is managing. This means using the suit for buoyancy.
If the diver is not over-weighted (and so many are), you're only looking at 2-3l of "extra" gas in the suit anyway - that's not a lot.
Once that diver's skills improve, *then* is the time to be adding complexity to the situation.
Vic.
Nigel Hewitt
16-04-2006, 14:14
No matter what the argument for and against using BC/Suit etc. in the early days it is far better to use BC for bouyancy and suit for warmth, no question.Oh Dear! I'm agreeing with Terry again.
The 'Oh it's too hard for the poor dears to manage two sources of buoyancy' idea is completely fatuous. In a proper drysuit with the autodump wound wide open all they have to do is push the inject button to get it in when the squeeze becomes noticeable and otherwise ignore it.
OK if they are diving something that Noah's ship's diver cast off with a cuff dump they are going to have to fight it as any arm movement has buoyancy implications. If we make things hard for people they will have trouble. If we make it easy they will enjoy their diving and be safe.
Buoyancy control is a matter of managing weighting and air space. Why not just stick to teaching people how to manage the airspaces? How they decide to use them is their decision. It's quite a flexible approach as it works for all divers whatever equipment they happen to wear. It takes a bit more time than teaching up-button/down-button though.
If students don't appear to have a major problem I suggest ways they can improve buoyancy control. If they are having a problem I have no qualms suggesting they try altering their technique.
I am reminded of a guy that popped into the club some years ago and mentioned that he was struggling with buoyancy since buying his dry suit and asking how it should be used on an internet forum. It was suggested that he might try ignoring the internet pundits and just use the suit for buoyancy. He came back the following week gushing about how well he had got on and joined up.
I am not going to assume what problem an individual has until I have seen them inwater. I have occassionally suggested people try using the stab jacket and that has helped them. The majority of people I have helped with buoyancy control have faired better using just the suit intially.
...and if I wind my autodump _wide_ open, I get shrink wrapped by about 6m!
Buoyancy control is a matter of managing weighting and air space. Why not just stick to teaching people how to manage the airspaces? How they decide to use them is their decision.
NO no no no no no no! You forget one very important factor here ..... indeed, it appears to have been overlooked by all contributors to this thread and that is "my way is right!"
:) :) :)
Nigel Hewitt
17-04-2006, 15:53
...and if I wind my autodump _wide_ open, I get shrink wrapped by about 6m!That's right. You should be topping up the drysuit about as often as you clear your ears.
It's all about control not brute force and ignorance.
is "my way is right!" If it results in a comfortable, enjoyable dive with little risk of being a burden to CG and NHS, I could not agree more ;)
Hey guys the clue is in the name.
Bouyancy Compensator or Buoyancy Control - Guess what it does?
That's right does your Bouyancy.
Dry suit - Guess what that does? Yep it keeps you dry (or should do).
T
David
If we taught correct weighting & being neutral bouyant, correctly, far fewer people would be using BC's for bouyancy, because there is just no need!
I seem to spend most of my time on Advanced Nitrox courses attempting to remove huge amount of excess lead from candidates. Why does any one on a single 12l +3l in a membrane drysuit need 10kg of lead???
Whats even more frustrating, is having proved they don't need all that lead they promptly put it back on when they leave & teach the same poor practice to those they dive with!
We teach people to be overweighted from day one of training. A steel 12 litre in fresh water and a swimming costume does not need a weight belt. Yet the average club pool has trainees stuck to the bottom of the pool all through their training - normally with weight belts with 4 to 8lb on it.
It is not suprising that when divers get into open water they like the heavy feeling - and they never get out of the habit. Weighting the student heavy is for the convenience of the instructor not for the education of the student.
Tony
David Walker
17-04-2006, 22:07
It is not suprising that when divers get into open water they like the heavy feeling - and they never get out of the habit. Weighting the student heavy is for the convenience of the instructor not for the education of the student.
Interesting comment. A lot of the stuff we do in the water for OD and SD involves sitting on the bottom doing skills. It certainly is a little easier if they are that bit heavier, rather than floating off half-way through a mask clear (which many would because they tend to have a big lung full of air while they're doing it). Might be worth getting people to do skills while still neutrally bouyant, rather than getting them to dump their air as we currently do? I'm sure I heard somewhere that GUE's coming entry-level qualification would approach it this way, doing all the skills mid-water - midwater might be a bit adventurous in the current 5 dives of OD or whatever, but at least neutrally bouyant with just the fins touching the bottom...?
David
Bouyancy Compensator or Buoyancy Control - Guess what it does?Yeah Yeah. I carry a Compact Disk in my dive kit. Guess what it does?
Your suit provides buoyancy.
Your buoyancy compensator provides buoyancy.
They both need to be controlled.
doing all the skills mid-water - midwater might be a bit adventurous in the current 5 dives of OD or whatever, but at least neutrally bouyant with just the fins touching the bottom...?David get yourself a CCR and do the course. It certainly has helped remind me how difficult simple things can be when you are first starting out. Considering the last time I practised a mask removal on OC for myself, I was hovering upside down at 6m on a night dive...I was stunned, shocked and very frustrated to find myself forced into kneeling on the sand during my CCR course. Not because my instructor wanted me to, but because it was the only way I was going to complete it.
AFAIC the answer is exactly what I am currently doing with the CCR. Conditioning to pre-empt and control the buoyancy sources, regular buoyancy checks until weighting stabilises and trims right, dive shallow until you are capable and confident controlling buoyancy.
AFAIC the answer is exactly what I am currently doing with the CCR. Conditioning to pre-empt and control the buoyancy sources, regular buoyancy checks until weighting stabilises and trims right, dive shallow until you are capable and confident controlling buoyancy.
Matt
I'm going through the same pain at the moment.
Guess what - I'm wearing too much weight, as a result I am putting air in the wing to help me trim my bouyancy This is why I know I am wearing too much lead.
I had the weighting right in fresh water, a month or so back, suddenly a little squirt of air to make the drysuit comfy & I was perfectly trimmed, no air in the wing, minimal loop volume.
This weekend I had this years first sea dive with the CCR. Back to needing the wing to compensate for the fact I had over done the amount of lead (2kg + "just a bit extra to make sure")!
With a CCR, wing & drysuit you now have three volumes - & two hands!
If you get your weight right there is negligible amounts of air required to get you neutral!
The switch to CCR has increased my sensitivity/ awareness to correct weighting. Something I had taken for granted on OC.
Gareth
Hey guys the clue is in the name.
Bouyancy Compensator or Buoyancy Control - Guess what it does?
That's right does your Bouyancy.
Dry suit - Guess what that does? Yep it keeps you dry (or should do).
T
Yes, but the correct full title is BDCFTWWBSBFTWD which, as everyone knows, is the acronym for 'buoyancy control device for those wearing wetsuits but surface buoyancy for those wearing drysuits'.
Not that I have a problem with people showing off and managing two expanding gas sources on ascent (or vacuum packing themselves and just managing their wing/BCD). However, I'm a man (Betty) and can only concentrate on one thing at a time :) ......................... hmmmmmmm, I wonder if there are more women divers than we thought .............. Jeez, some of them are quite hairy! :)
I can see it in the diving press ...... SHOCK NEWS. BSAC's internet forum members discover there are lots of female tranny divers!
Has anyone got the number for the Sunday Sport?
:):):)
AndyDavis
19-04-2006, 18:07
If you look at the BSAC safe diving practices, it also states that when a drysuit is used the suit is to be used to control bouyancy underwater, & the BC is to be used for surface bouyancy only.
Gareth
Not relevant to this discussion really, but this 'Safe Diving Practice' is ludicrous if the diver is carrying twinset/stages/tools etc....as a drysuit would not offer sufficient bouyancy/lift to compensate without becoming an absolute liability. A BC (or wing) is designed to provide bouyancy, the Drysuit is not. I've yet to see a drysuit with emergency pull-dumps or reinforced seals (to cope with large volumes of 'working' air).
Andy
If you look a little further down the thread (or the related thread), I do accept in exceptional circumstances you end up using both drysuit & BC.
However, if you are talking about those learning to dive, at ocean diver level, thay are going to be carrying minimal amout of weight in terms of cylinders & gas.
What is frustrating is that rather than address the problem of individuals carrying too much lead, & being over weighted. The result of which is that they now need large amounts of air to maintain neutral bouyancy, we then seem to teach them techniques to accomodate the excessive amounts of air. Rather than addressing the fundimental problem - they are carrying too much lead.
Once people have 'decided' the need 10kg of lead to dive a membrane with a 12l steel cylinder, & have been doing this for any period of time. It is very difficult to change their mind. I would prefer it if we did this from the outset! rather than let them ingrain poor practice.
Gareth
I've yet to see a drysuit with emergency pull-dumpsEvery dry suit has them. They call them neck and wrist seals.
R.Burgess
27-04-2006, 19:46
After my first day of dry suit diving I had hicky like weals on my legs and finished a 12 litre in under 20 min diving at a depth no greater than 6m. I was told to work some air into my legs. On my 2nd day of dry suit diving I did a feet first ascent and couldn't get upright without help. Somehow I've never been able to do it again.:D
After my first day of dry suit diving I had hicky like weals on my legs and finished a 12 litre in under 20 min diving at a depth no greater than 6m. I was told to work some air into my legs. On my 2nd day of dry suit diving I did a feet first ascent and couldn't get upright without help. Somehow I've never been able to do it again.:D
Aren't hickys, like cooties, caught from girls? Were you wearing ladies tights ......or maybe...... stockings? :)
Well, the top 10 mtrs of the sea does constitute the region with the greatest buoyancy change over depth .........
Not able to do it again? Are you talking about hickys?
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