Bouyancy problem

[dogglebe]

Tonight, I had my first confined water dive and had some bouyancy problems; I was too bouyant. The instructor said that my wet suit was too big for me and was keeping pockets of air inside. Wouldn't these bubbles eventually work their way out of the suit?

For what it's worth: I'm 6' 2", 202 pounds. I wore a 7mm Seaquest farmer john style, size XXXL. The suit feels snug, though I could occasionally feel the water moving around inside it.


Phil

 

[Dr Wu]

Eventually yes but unless the pool was Nemo 33 probably not.

From what little I can see here your instructor is most likely correct. A fitting 7mm should feel absurdly tight on the surface.

Either way props to your instructor for not just sticking more lead on you.

Was it a pool? If so why were you wearing a 7mm?

 

[idocsteve]

It would be helpful to know how much weight you were wearing.

For a whole bunch of reasons.

There's also a bunch of reasons why you don't want water moving around inside your wetsuit.

Training is also a time to learn how to determine if your gear is fitting you properly and what happens if it doesn't. A loose wetsuit won't keep you as warm.

 

[Codiak]

As a general rule, for 7mm in fresh water : 10% body weight + 6lbs should be fairly close

 

[Karl_H]

Hi Phil,

I don't think anyone has made their first confined or open water dive without having problems with too much buoyancy

I'm also 6'2" (although sadly closer to 250 lbs than 200!) and tend to find most wetsuits are far too tight between the crotch and the shoulders unless I go to XXXL, occasionally a XXL does work. I'd agree a loose wet-suit can give you problems with trapped air, but there can be worse implication of wearing a wetsuit that is far too tight. A overly tight wetsuit will restrict blood flow and leads to much higher chances of getting bent - if only a little bit. I've had a few experiences of tingles in my shoulder for a day or so after wearing a wetsuit that's tight on the shoulders, and that's even from non-deco diving!.

Water will eventually replace the air in the suit and remove it as you suggest, however this won't help if you're having problems at the start of the dive, although it will help at the end! Sadly a wet suit in which water can get in and out of with ease kind of defeats one of the main reasons behind wearing a wetsuit. I'd suggest trying a different suit, some brands have a different fit to others - a sad fact of life is good fitting wetsuits are hard to find, if you find one that fits well make sure you buy two

Out of interest what weight are you using? I'm a warm water diver so a 7mm wetsuit is bordering on a drysuit to me, but I'd guess you'll be using maybe 15-18lbs with an Aluminum tank if you're just starting off? The usual problem is air in the lungs rather than air in the wetsuit, there lots of threads on here how to avoid that. If your still on confined water dives try the same dive without the wetsuit on but with everything else the same and check your buoyancy, then try with the wet suit and add around 5-8 lbs (is this right for a 7mm wetsuit?) to see if you can get the same buoyancy. If you can it's not trapped air in the wetsuit, if you need to add 12lbs or more then it looks like the wetsuit is the problem!

Hope that helps!

Karl

 

[rab1412000]

Tonight, I had my first confined water dive and had some bouyancy problems; I was too bouyant. The instructor said that my wet suit was too big for me and was keeping pockets of air inside. Wouldn't these bubbles eventually work their way out of the suit?

For what it's worth: I'm 6' 2", 202 pounds. I wore a 7mm Seaquest farmer john style, size XXXL. The suit feels snug, though I could occasionally feel the water moving around inside it.


Phil

its quite hard to tell whether its your suit, your weights, or your skills thats causing this since you are fairly new.
and the thicker the suit is the harder it will be to control bouyancy.
although the feeling of water moving inside it may suggest a too loose fitting suit, it could just also be you trying to get used to using a wetsuit in general.
assuming youre properly weighted (since you got your instructer ), youre best bet would probably be to try a different model/design and see how that goes- as mentioned above. i also find farmer johns retain more air bubbles than your normal wetsuit and it takes me some time to achieve neutral bouyancy during the start of the dive ( i usually dive .5-3 mm wetsuits).

 

[driftwood]

As a general rule, for 7mm in fresh water : 10% body weight + 6lbs should be fairly close

Are you suggesting 26lbs of weights? Seems a bit excessive to me.

 

[Codiak]

Are you suggesting 26lbs of weights? Seems a bit excessive to me.

It doesn't account for BMI or skill level and normally allows descent with padding for alum tanks. Proper weighting should be part of the class.

 

[Interceptor121]

Tonight, I had my first confined water dive and had some bouyancy problems; I was too bouyant. The instructor said that my wet suit was too big for me and was keeping pockets of air inside. Wouldn't these bubbles eventually work their way out of the suit?

For what it's worth: I'm 6' 2", 202 pounds. I wore a 7mm Seaquest farmer john style, size XXXL. The suit feels snug, though I could occasionally feel the water moving around inside it.


Phil

Air trapped should find its way out as you descent and then no other build up should occur unless you fart a lot. Even in that occurrence you should not become positive right away but feel bubbles escaping.
Try doing a few stretched and sit up before donning the BC the air should come out

 

[Crowley]

26 lbs sounds like a lot but might not be quite enough; you're a big fella in a thick wetsuit and I was teaching a guy last week who was maybe 6', 180lbs and pretty muscular and he needed 12 kgs (about 26lbs) for proper buoyancy. Okay, yes we are in saltwater but I've seen people wearing 16 kilos (35lbs ish) in rental equipment.

On the other hand, it could actually be too much (everybody's different); a common cause of excessive bouncing up and down is too much lead on the belt, meaning yo have to put too much air into the BC to compensate - for even a small decrease in pressure this is enough to cause the air to expand excessively and start to pull you to the surface.

Points to note: If your wetsuit was too big it is unlikely to be trapping air, and anyway it's a wetsuit, and therefore not waterproof, the air should work its way out all by itself unless it's a suit with seals, in which case it's a semi-dry, not a wetsuit, with different buoyancy characteristics (lots more buoyant).

Second point - as mentioned before, it's your first confined session. If you had great buoyancy first time around we wouldnt need training and courses!

Cheers

C.

Points to note. If your wetsuit is