Wet Suit Compression/Expansion

[shotthebreeze]

When I was doing my checkout dives this July I ran into a slight problem. We dove down in to a rock mass with a bunch of lobsters and hung around there at about 35 feet for 15 or so minutes. When coming back up to about 20 feet, my compressed wetsuit expanded and I floated to the top with my BCD totally deflated and 33 pounds still attached.

To me, this could be very dangerous if I were diving at a deeper depth and I was on my way to my 15 ft safety stop. Are there any ways to prevent another accident like this from occurring?

 

[scuba70]

Wow!! Sounds to me like you would be dangerously overweighted! What kind of wetsuit were you wearing? This was during your checkout dive, what did your instructor have to say?!

 

[shotthebreeze]

Wow!! Sounds to me like you would be dangerously overweighted! What kind of wetsuit were you wearing? This was during your checkout dive, what did your instructor have to say?!

I had a 7mm farmer john on with gloves and boots, so for an inexperienced diver, the weighting was about right. I did the buoyancy check and I wouldn't descend with anything less. Afterward, my instructor just explained to me what happened and not much more...

 

[rrjc5488]

That souns very odd. If you were able to descend with that much weight from 0-20 feet you shouldnt have shot up like that. The only explination I could think of for that would be if descending you descended head first, and your bubbles floated into your wetsuit opening (farmer john style is easy for this to happen) then, when you ascended the trapped air in your suit expanded.

 

[TSandM]

Well, solving this problem starts with doing a good, formal weight check. This can be done in shallow water, making sure the BC is COMPLETELY empty. Your goal is to float at eye level with a normal breath, and sink when you exhale. This can be done with a full tank, if you weight to the parameters described, and then add the weight of the gas you are carrying, or it can be done by emptying a tank to the psi you would like to use for your minimum reserve (often 500 psi, although I prefer to go a little lower).

Without doing this, you can't really know if you were underweighted, or if you were unsuccessful in venting the BC, or if you got nervous when you started to get light, and were holding too much air in your lungs (which is easy to do when you are new). Some BC's don't vent completely without significant gyrations on the part of the diver (they trap air). But breathing is a BIG part of buoyancy. Even properly weighted and relatively experienced divers, when tackling heavy task-loading, can find themselves losing buoyancy control simply because they lost control of their breathing.

So, do a weight check. My guess is that you are probably at the very least adequately weighted, and if you are of normal body habitus, may be overweighted. Once you are sure the weight is adequate, keep your dives shallow and work on figuring out how best to empty your bc, and how to control your breathing.

 

[shotthebreeze]

The only explination I could think of for that would be if descending you descended head first, and your bubbles floated into your wetsuit opening (farmer john style is easy for this to happen) then, when you ascended the trapped air in your suit expanded.

Went down fins first on the anchor line...it is very odd. I can't figure it out or how to prevent it...

 

[shotthebreeze]

Well, solving this problem starts with doing a good, formal weight check. This can be done in shallow water, making sure the BC is COMPLETELY empty. Your goal is to float at eye level with a normal breath, and sink when you exhale. This can be done with a full tank, if you weight to the parameters described, and then add the weight of the gas you are carrying, or it can be done by emptying a tank to the psi you would like to use for your minimum reserve (often 500 psi, although I prefer to go a little lower).

Without doing this, you can't really know if you were underweighted, or if you were unsuccessful in venting the BC, or if you got nervous when you started to get light, and were holding too much air in your lungs (which is easy to do when you are new). Some BC's don't vent completely without significant gyrations on the part of the diver (they trap air). But breathing is a BIG part of buoyancy. Even properly weighted and relatively experienced divers, when tackling heavy task-loading, can find themselves losing buoyancy control simply because they lost control of their breathing.

So, do a weight check. My guess is that you are probably at the very least adequately weighted, and if you are of normal body habitus, may be overweighted. Once you are sure the weight is adequate, keep your dives shallow and work on figuring out how best to empty your bc, and how to control your breathing.

As I stated before, I did the weight check and was neutrally buoyant. My instructor made us all do it while hanging on to the ladder on the back of the boat.

 

[Teamcasa]

Your wetsuit will compress at depth and expand to its original size as you assent, that’s a trait common to any type of wetsuit.
Buoyancy control is something you will only learn from experience and practice. The situation you describe is fairly common for new divers that have not figured out how to control their assents. I suggest you practice ascending at a much slower rate, something like 5 -10 feet per minute, watch your SPG and try holding for a full minute at each 5 foot interval. You will soon figure it out. Just dive more.

Dave

 

[scuba70]

As you become more comfortable in the water you should be able to shed many many pounds! I don't really buy the wetsuit expansion thing with that much wieght on. Did I read correctly, 33 pounds?! I'd recommend that you do a lot more diving, with focusing on bouancy control. Don't do anything crazy, but just get some experience in the water. I wear a 5mm farmer john and I only wear 16 pounds. I can't imagine it would be much more than that.

 

[shotthebreeze]

As you become more comfortable in the water you should be able to shed many many pounds! I don't really buy the wetsuit expansion thing with that much wieght on. Did I read correctly, 33 pounds?! I'd recommend that you do a lot more diving, with focusing on bouancy control. Don't do anything crazy, but just get some experience in the water. I wear a 5mm farmer john and I only wear 16 pounds. I can't imagine it would be much more than that.

Oh you read correctly, 33 pounds. It was a pain in the **** to get back on the boat with all my gear. I'd love to start shedding the weight, but as you said, that will come in time. I guess I just need to do more diving...without shooting to the top. Perhaps a trip to Belize with a shorty may be in order . Nah, if you can dive in New England you can dive anywhere...