Dry suit shells (from a person who obviously knows nothing about them)

[PolsVoice]

How warm of water can you use a dry-suit if it is only a shell designed for use with thermals underneath.

If I go with a shellsuit wearing only my swimtrunks in 70F+ water, is it really that easy to overheat? I know that my body would heat up the air in the suit, but would it really bring it up to hyperthermia levels?

Just curious,

- PV

 

[Boogie711]

In the water isn't usually the problem. It's standing in the sun waiting to get in the water that's usually the issue.

There are a lot of people, especially up here, who have a drysuit and a 3mm. If it's tropical warm goodness type water, they'll grab the 3mm, anything less than that, it's diving dry with various levels of undergarments.

 

[SubMariner]

In the water isn't usually the problem. It's standing in the sun waiting to get in the water that's usually the issue.

There are a lot of people, especially up here, who have a drysuit and a 3mm. If it's tropical warm goodness type water, they'll grab the 3mm, anything less than that, it's diving dry with various levels of undergarments.

Complete agreement on this one.

BTW PolsVoice, just wearing a bathing suit under a drysuit is a bad idea. Not only will you wind up soaking wet from sweat (nothing to wick it away) but you can also get a little nasty thing called a "suit hickey", especially in areas like the back of the knees and inside of elbows.

The solution to this is to wear thin long sleeved shirts & leggings under the suit in "warmer" water. Works a treat!

 

[theskull]

I wear my drysuit with bicycling tights underneath in water temps between 75-80 F. That is if I'm also going to be making deeper dives in colder water on the same trip. Otherwise I leave the suit home and take a 3 mm wetsuit.

theskull

 

[hex92]

Drawing on my vast drysuit experience....last night in the pool. I can attest to the fact that just wearing a swimsuit underneath is not very comfortable. I didn't check the back of my knees, but I do have suit hickeys on the inside of my elbows.

I can't wait to dive in some cold water so I can put on my full complement of undergarments. I should be much more comfortable.

 

[mempilot]

I wear my drysuit with bicycling tights underneath in water temps between 75-80 F. That is if I'm also going to be making deeper dives in colder water on the same trip. Otherwise I leave the suit home and take a 3 mm wetsuit.

theskull

Ditto here. I wear a thin wicking material over the whole body for 72 and up. You can vent the suit between dives to stay cool. Stay in the shade. Or get out of the top half if your surface interval is long enough. For colder than 72, I layer light or medium fleece.

Unless you have some natural insulation , even a 3mm will put you into hypothermia in temps below 75. You can get hypothermia in any water that is colder than your core body temp. As the differential between your body and water temps increases, the less time to hypothermia. The first dive is usually not the problem. It's getting out and then back in for the repetive dives.

Wear the drysuit, stay dry, no more hypothermia. BTW, many divers get hypothermia and don't realize the symtoms. They think they are just cold. This is dangerous to divers since hypothermia increases the risk of DCI as well as other potentially harmful effects.

 

[PolsVoice]

BTW PolsVoice, just wearing a bathing suit under a drysuit is a bad idea. Not only will you wind up soaking wet from sweat (nothing to wick it away) but you can also get a little nasty thing called a "suit hickey", especially in areas like the back of the knees and inside of elbows.
QUOTE]

What causes suit hickey? Is it just abrasion, or is their some sort of vaccuum produced, like what causes a real hickey...

cool.

- PV

 

[Boogie711]

As you descend, the air space in your suit compresses... the water WANTS to get in to equalize, but it can't. You don't have this problem in a wetsuit.

As you get deeper, your suit becomes tighter and tighter. You add little squirts of air to your suit to alleviate the squeeze, but the more air you add, the more unstable you become. Hence, it's safer and much easier to dive with a fair amount of 'suit squeeze' - leaving suit hickeys if you're not wearing something underneath.

 

[SubMariner]

What causes suit hickey? Is it just abrasion, or is their some sort of vaccuum produced, like what causes a real hickey...

It's sort of a combo of the two: you get suit squeeze if there is no pressure (air) in the suit to offset that of the water on the other size of the material. So the material winds up binding & adhearing in the jointed areas like behind the back of the knees & in the crooks of the elbows.

Of course, this is most common in shell drysuits. It is rare in 5mm neoprene drysuits because of the bulk of the material, but it CAN happen if you are deep enough.

As you get deeper, your suit becomes tighter and tighter. You add little squirts of air to your suit to alleviate the squeeze, but the more air you add, the more unstable you become. Hence, it's safer and much easier to dive with a fair amount of 'suit squeeze'

Sorry, you'll get some dissenters on this point, and I'm one of them. Using the suit for buoyancy control u/w is just as controllable as the method you describe. It is merely a matter of preference and training.

 

[mempilot]

Sorry, you'll get some dissenters on this point, and I'm one of them. Using the suit for buoyancy control u/w is just as controllable as the method you describe. It is merely a matter of preference and training.

Well, not really. You may have learned to control your attitude underwater while using your drysuit as a bc. But, containing an air mass over the center of buoyancy will be much more controllable than dispearsing it over your entire body. A diver's mass concentration is in the torso and head, not in their legs. By allowing a distributed air mass at such a distance from the center of bouancy does cause control issues. I'm not saying you can't or shouldn't dive this way. I'm saying it is defineatly easier and more efficient to use the bc for a bc and the drysuit to stay warm with only enough air to eliminate heavy squeeze and provide an insulating layer.