Drysuit Squeeze questions

[piikki]

Uncle Pug gave a great description of what the squeeze should feel like in a post long ago. He called it the "20 foot squeeze". Vent all the air from your suit and drop to 20 feet, that is what the squeeze should feel like the entire dive.

Uoh... I wonder if this is why I am having probs lately. I do not like to have that much squeeze - not because the squeeze/discomfort itself but because it restricts my movement to go that tight, especially arms. I add a puff at 10 ft, and I stay happy.... however I must dive head little down because I always get squeezed in my armpits first, and air always collects to my calves. I'd rather take your problem of tight legs - even though I have managed to get my bikini top imprinted on me only once. Light legs suck.

 

[Dive1Dennis]

Actually there are two schools of thought on this. Some people are trained to use the BC for buoyancy and the air in the suit to relieve squeeze. Others are trained to use the suit for buoyancy. Once you dive a drysuit for a while you will develop a preference and its easier to use the BC for buoyancy rather than the suit. You aren't committing any kind of crime by doing so. Personally I don't use the suit for buoyancy.
Ber :lilbunny:

Agreed. Suit to offset the squeeze. BC for buoyancy control.

 

[Uncle Pug]

You don't need to use a 20' squeeze if that feels too tight for you, especially if it restricts your movement and/or ability to reach your tank valve.

If you need a 10' squeeze to stay comfortable (and warm) that is fine. The idea is to eliminate the big bubble of air that can move unrestricted from neck to feet and contribute to dynamic instability.

On descent (horizontal) I hold my arms out in front of me, clasp my hands and stretch from side to side to keep the suit material distributed evenly from foot to wrist. This gives me the flexibility I like while also allowing me to assume and maintain any orientation underwater without having air rushing too and fro inside my suit.

Do what works for you.

 

[cummings66]

I believe maintaining some amount of squeeze to be beneficial, especially to newer drysuit divers. I can do it either way but tend to use the BC for a BC and the drysuit to stay dry.

If I get cold for some reason I'll add more air to the suit and dive it the way Padi trains you to, otherwise I do it the other way. For what it's worth, I like the 20' foot squeeze feeling. Without knowing it, that's what I stumbled across after dozens of dives getting the feel of the suit. I saw that posting and thought, gee, if I had known that to start with I'd have had many more fun dives...

 

[Thalassamania]

The definitions are not clear here. One should use the ABLJ/BC/BCD/Wing to with the shift in the weight of the tank due to the use of gas during the dive (and the shift in buoyancy due to compression/expasion of gas in the ABLJ/BC/BCD/Wing). The dry suit should have gas added to it and have the vavle set so that it maintains (more or less) constant volume through the dive.

 

[GeeGee]

The definitions are not clear here. One should use the ABLJ/BC/BCD/Wing to with the shift in the weight of the tank due to the use of gas during the dive (and the shift in buoyancy due to compression/expasion of gas in the ABLJ/BC/BCD/Wing). The dry suit should have gas added to it and have the vavle set so that it maintains (more or less) constant volume through the dive.

I am pleased to read this thread on squeeze. I have had the opposite problem of squeeze in my arms this winter. Throughout summer and early fall I rarely needed air beyond controlling squeeze in my drysuit, but now, I need a little more air for warmth but find I can't eliminate the squeeze in my arms and hands (dry gloves). I have tried extending arms, raising legs past horizontal, etc., to distribute air, to no avail. My weight seemed right in the warmer water but I have added two more pounds to enable me to add a little more air for warmth. I am struggling with getting light towards the end of my dive. I have never thought to change the adjustment on my suit valve from a few clicks back from wide open to control air volume. Is it a good idea to close the valve, add air to the suit, and then use only my wing for buoyancy control.? Closing the valve would eliminate accidentally venting air from my suit when venting my wing but adds to the problem of runaway ascents. Is it better to go lighter on the undergarment in order to be able to have room for more air?

 

[Daryl Morse]

The answers here are simple physics. The total amount of air you can carry between your wing and your suit is determined by how negative you are. If you need to be able to carry more air, you need more weight . . . This is why dry suit diving is heavy weight diving, because a dry suit obligates you to carry a certain amount of air down with you.

Air goes to the highest point in whatever contains it, so unless you are horizontal, you cannot keep air in your legs and feet. The more vertical you are, the more noticeable the difference between your shoulders and your legs will be.

A dry suit bubble is a big bubble and potentially pretty unstable, which is why dry suit classes teach you methods for redistributing the air in the suit to avoid feet-first ascents. The smaller the amount of air you carry in the suit, the less risk there is of that kind of problem. But less air means less warmth AND less mobility, and there is a point where it's too much squeeze.

I found it was much easier to learn to manage the suit by using the "20 foot squeeze" idea, but now that I'm much more comfortable with my dry suit, I run it looser than that, which has increased my cold-limited time underwater and made it much easier to reach my valves.

A final note: Ideal weighting is determined with the wing AND the suit empty, but many people decide to carry one or two extra pounds to allow a little more suit air for comfort and warmth.

Excellent post. I couldn't agree more.

 

[Mel.B]

Thanks for all the posts and thoughts. I'm going to head out this weekend and work on my trim some more which I think is my biggest issue. I don't want this thread to end up as a drysuit vs. drysuit + BC for bouyancy control aurgement - there are enough of them here already. Suffice to say I've decided what method I prefer and that's the one I'll be using.

Mel.b

 

[SparticleBrane]

My personal thoughts--
Why would you want to use the drysuit to control buoyancy? If this were the case it'd be called a "Buoyancy Suit" instead of a drysuit. Drysuit is there to keep you dry and can be used as backup buoyancy in the event of a main BC failure. Use the drysuit to keep you dry and the bp/w or BC to control buoyancy.

This is all IMHO of course.

 

[dbulmer]

SparticleBrane,
A dry drysuit is a novel concept - do you think it might catch on sometime?