Dry Suit Death?

[dbg40]

Yeah.... That kind of stuff can ruin a good weekend.

 

[detroit diver]

A number of years ago, I descended without hooking up my inflator hose to my drysuit. I didn't both me until I hit about 75 feet or so, and by then, the shrinkwrap feeling had set it pretty hard. Fortunately, I had enough movement to slow my descent, and signaled to a friend. He attached my hose and everything was good.

While I don't think you'd squeeze like toothpaste, I can see where the restricted movement could prevent you from taking the steps necessary to halt the descent, with some nasty potential issues from there.

 

[H2Andy]

I think he's referring to the incident on the empress of Ireland almost
100 years ago now that is mentioned in _Dark Descent_? I'm guessing they didn't
have a non-return valve in those days so if you slipped off the wreck you'd build up a
differential pressure between ambient water and the hose and get sucked up the hose...

that's exactly the one i read about

so basically, the squeeze on a dry suit would hurt, but it would stop at some
point?

of course, like detroit diver says, if you can't move your hand to inflate,
you're on an elevator ride to the bottom with no way to stop it

 

[Web Monkey]

ok... so.... i was reading about how hard-hat divers in the old days could
get "squeezed" into their brass helmet by pressure if their suit somehow couldn't
keep up with the external pressure.
basically, they ended up as a ball of flesh in the helmet.
so... being new to dry suit diving, i got to wondering:
can suit squeeze kill you?

Suit squeeze is uncomfortable, but is caused by the fabric of the suit bunching together, not the water pressure on you. When the ewater pressure is X PSI, your regulator is filling you with X PSI, so the pressure is equal (and you can breathe).

The water pressure on you is the same regardless if you're wearing a wearing a wetsuit or a drysuit. If you forget to add air, you can however get "hickeys" where the suit gets bunched up if it contacts your skin. They're embarrassing, but not fatal.

As you descend, you may notice that you're being squashed a little because of the bunched suit material, so you add a little air.

In fact, the uncomfortable feeling would remind you to add air. It's not something you would completely forget, then suddenly look like were tossed into a trash compactor.

The worst that would happen is you would get out of the water and look like you had a serious relationship with the creature that tried to suck the salt out of Capt. Kirk in Startrek.

Terry

 

[TwoTanks]

The type of accident you heard about, where someone is crushed into the helmet can only happen when there is a direct air passage to the surface.

Basically, what happens is that the air pressure at the surface is 1 ATA and if you were at 33 feet the ambient pressure around you is 2 ATA. If the compressor stopped and there was no check valve to hold the pressure in the hose, then the air would flow back out of the hose until it was at 1ATA (air pressure at sea level). Then the bottom end of that hose inside your helmet would have only half of the ambient pressure outside the helmet. Then the effect is the same as shooting out a plane window, greater ambient pressure at depth creates suction in the hose that is greater than any vacuum cleaner and just sucks everything in until the hose is full up to sea level. Unfortunately, the first thing to get sucked in is the helmet diver.

At 100' the suction is 3x as great as at 33'.

With a dry suit you can get a squeeze and some pain but you can never be subjected to several atmospheres of pressure difference.

TT

 

[H2Andy]

The worst that would happen is you would get out of the
water and look like you had a serious relationship with the creature that tried to suck
the salt out of Capt. Kirk in Startrek.

i remember that, dude!! :11:

and then try explaining it to your wife that night: "honey, it was the DRYSUIT,
i swear!!!!"

thanks all, for your answers

 

[theskull]

A number of years ago, I descended without hooking up my inflator hose to my drysuit. I didn't both me until I hit about 75 feet or so, and by then, the shrinkwrap feeling had set it pretty hard. Fortunately, I had enough movement to slow my descent, and signaled to a friend. He attached my hose and everything was good.

While I don't think you'd squeeze like toothpaste, I can see where the restricted movement could prevent you from taking the steps necessary to halt the descent, with some nasty potential issues from there.

Did you not have a BC or BP/W on? Even if you are still using your suit for buoyancy you can use the BC in the event of an emergency! The BC is redundant buoyancy for the suit should it flood--or better yet, the suit is redundant buoyancy for your BC should it fail.

Either way there is no excuse for a runaway descent when you have 2 separate buoyancy control devices on. If you forgot to attach both hoses you could still orally inflate the BC.

theskull

 

[H2Andy]

the skull, i think the problem was he couldn't move his arms due to suit
squeeze to reach either the BC or the suit inflator valve

 

[detroit diver]

Actually, it can get more than uncomfortable. The suit can constrict enough to restrict movement of your arms. I can imagine that it could restrict your diaphram also (yes, your breathing diaphram!!).

Yes, you will feel it in advance. It should give you time to fix the problem.

Suit squeeze is uncomfortable, but is caused by the fabric of the suit bunching together, not the water pressure on you. When the ewater pressure is X PSI, your regulator is filling you with X PSI, so the pressure is equal (and you can breathe).

The water pressure on you is the same regardless if you're wearing a wearing a wetsuit or a drysuit. If you forget to add air, you can however get "hickeys" where the suit gets bunched up if it contacts your skin. They're embarrassing, but not fatal.

As you descend, you may notice that you're being squashed a little because of the bunched suit material, so you add a little air.

In fact, the uncomfortable feeling would remind you to add air. It's not something you would completely forget, then suddenly look like were tossed into a trash compactor.

The worst that would happen is you would get out of the water and look like you had a serious relationship with the creature that tried to suck the salt out of Capt. Kirk in Startrek.

Terry

 

[Daryl Morse]

so... being new to dry suit diving, i got to wondering:

can suit squeeze kill you?

what if you accidentally drop down faster and faster, and somehow can't
hit the inflate button for the dry suit... will you be "squeezed to death?"

if so... how deep do you think you have to go before this happens?

If you think about it, the only thing that compresses when the drysuit squeezes is the undergarments. Your body is basically liquid, therefore it's essentially uncompressable. No different than diving with a wetsuit. A good analogy is vacuum packed coffee beans. Berfore you let the air in, they are quite tight in the package. When you let the air in, the beans loosen up.

If you neglect to inflate your drysuit as you descend, all that happens is it gets somewhat more difficult to breathe and you loose flexibility because the suit gets stiff. Sometimes you can end up with crease marks on your skin caused by squeeze. That said, I don't think it could kill you.