drysuit shell versus crushed neoprene.

[mossym]

To further elaborate.. assume you have a neoprene drysuit and you have a complete wing failure at the beginning of your dive at 100 feet.

You will suddenly be very negative and will almost certainly have to dump weight to get back up... and by the time you get near the surface you will be significantly *underweighed* and not be able to stay down.

couldn't you just use your suit for bouyancy, then vent as you ascend?

Note: Edited to include post i was referring to

 

[ScubaDadMiami]

couldn't you just use your suit for bouyancy, then vent as you ascend?

The drysuit is used to keep you dry. The wing is what you use for buoyancy. Only if you have a wing failure do you want to start resorting to using the suit for buoyancy.

By using the suit for gas instead of the wing, there is a large area inside of the suit that can trap gas before you vent it. You could be rocketing to the surface before you could vent the suit.

Just put enough gas in the suit to avoid squeeze.

 

[Amphibious]

Diving a trilam means never having to worry about boyancy change (suit).

there is a reason 90% of the tec crowd and ALL the DIR crowd use trilam suits.

 

[mossym]

The drysuit is used to keep you dry. The wing is what you use for buoyancy. Only if you have a wing failure do you want to start resorting to using the suit for buoyancy.

By using the suit for gas instead of the wing, there is a large area inside of the suit that can trap gas before you vent it. You could be rocketing to the surface before you could vent the suit.

Just put enough gas in the suit to avoid squeeze.

i was replying to jonnythan's post, who mentioned wing failure..i understand the reasons for not using the suit for bouyancy, but he gave a scenario with wing failure, i should have quoted it.

 

[Amphibious]

Just my 2 cents....
I prefer the neoprene dry suit for several reasons.....
1) The material itself is warmer.
2) The material is safer.


By safer I mean the bouancy characteristics of neoprene. And, as well, a well made, form fitting suit will not allow excesive air content in the suit, providing a more stable diving situation.

I would argue these reasons make neoprene LESS safe. jonnythan spelled it out nicely

 

[DA Aquamaster]

To further elaborate.. assume you have a neoprene drysuit and you have a complete wing failure at the beginning of your dive at 100 feet.

You will suddenly be very negative and will almost certainly have to dump weight to get back up... and by the time you get near the surface you will be significantly *underweighed* and not be able to stay down.

Oh Lord, give me the strenght to endure those who do not understand...

It ain't rocket science.

Whether the neoprene compresses or the air in your insulation compresses makes no difference at all. Nada. Zip. Zero. Everyone understands that wet suits compress and get negative at depth because the neoprene compresses. Well, assuming you could stand the pain from the squeeze, if you dove your trilam drysuit to a 99 ft without adding air you would find that you are incredibly negative due to the air in your insulation being compressesd to 4 ATA. You would in fact be more negative than you would in a 7mm neoprene drysuit which compresses slightly less than an equivalent volume of air (and in which incidentally you probably could stand the squeeze.).

Consequently, a wing failure with a neoprene drysuit is no different that with a shell type dry suit. I know. I have practiced that evolution at depth in both types of suits. Do not confuse the limitations of a neoprene wet suit with a neoprene drysuit where you can add air - just like any other drysuit.

With either type of suit you crank the exhaust valve closed to allow more air to be held in the suit and you then inflate and use the suit for redundant bouyancy during the ascent. Even with a snug fitting neoprene suit, you can pump a lot of air in them becuase the material stretches. As you ascend, you vent the suit as needed and can then stop at the deco/safety stop(s). It is really no differnent in that regard than a trilam.

I cannot think of any technical diving situation where you would want to or ever need to dump weights except may be at the surface to establish additional bouyancy. Deco diving and dumping weights are just not compatible with each other.

I do find a neoprene drysuit to be more ammenable to unusual attitudes as they do not tend to allow excess air to rush to your feet if you are head down as will potentially happen even in a well squeezed trilam suit. I used to have to carefully contemplate and preplan getting into head down positions in a trilam but I don't have to give it a second thought with a neoprene drysuit. They really do swim better than a shell suit in every regard.

Just a thought, but how about we add some weight to our opinions from this point forward and actually mention whether we have dove both either one or the other or both types of suits. It will help cut through the dogma, speculation, misinformation and "I heard somebody say that" comments on the subject.

 

[mossym]

With either type of suit you crank the exhaust valve closed to allow more air to be held in the suit and you then inflate and use the suit for redundant bouyancy during the ascent. Even with a snug fitting neoprene suit, you can pump a lot of air in them becuase the material stretches. As you ascend, you vent the suit as needed and can then stop at the deco/safety stop(s). It is really no differnent in that regard than a trilam.

thanks..that's just what i thought..

 

[ColdH20diving]

I would argue these reasons make neoprene LESS safe. jonnythan spelled it out nicely

please, jonnythan missed the boat on this one.

 

[mahjong]

Overall, when the neoprene suit fits RIGHT (and proper fit is key in a neoprene suit), I find it offers a more comfortable, smoother-swimming, and warmer dive. It's nice wearing only a skin-tight Aeroskin polypro (and maybe a polartec powerstretch vest if need be) and being toasty with a snug fitting neoprene drysuit on top of it. Moreover, I find air moves much more efficiently inside the neoprene suit than the trilam--so exhausting air is a snap--there's no trapping inside the suit. Perhaps the only drawback is that you do need to carry more weight to get you down and then hold you down during deco or safety stops. And then MAYBE there might be some more air adjustments needed at depth changes and as tank air depletes. But some skill/practice (and maybe a removable 5 pound weight that you clip to the bottom of the anchor line on the way out and pick up on the way up) minimizes this inconvenience--and I find it fun. As far as saftey goes--there are many issues to consider (more than I can anticipate); however, in the end, stripped of everything (BC, weights), you float in neoprene and sink in trilam.

If money is NOT an issue, you can come close to finding some semblance of a middle ground with the CF200 compressed neoprene. Tight-fitting powerstretch underwear (expensive) and a snug fitting CF200 (which does stretch) creates something like the low-drag, slick feel you get with a neoprene drysuit. And you carry less weight with the CF200--so here it is more like the trilam. The CF200 is MIGHTY tough stuff and doesn't seem ever to wear out--if you take care of it, it'll be like new after a 1000 dives (no matter what depths you go to). So for those looking for a middle ground, CF200/powerstretch might be the way to go--but this is an expensive set up. (And yes, trilam does of course dry faster than neoprene/CF200.)

As for seals: Latex is more comfortable and easier to get in and out of. But if you make sure your neoprene seals fit right, they are not too uncomfortable and are much more durable and much warmer.

My belated two-cents.

Mahjong

Oh Lord, give me the strenght to endure those who do not understand...

It ain't rocket science.

Whether the neoprene compresses or the air in your insulation compresses makes no difference at all. Nada. Zip. Zero. Everyone understands that wet suits compress and get negative at depth because the neoprene compresses. Well, assuming you could stand the pain from the squeeze, if you dove your trilam drysuit to a 99 ft without adding air you would find that you are incredibly negative due to the air in your insulation being compressesd to 4 ATA. You would in fact be more negative than you would in a 7mm neoprene drysuit which compresses slightly less than an equivalent volume of air (and in which incidentally you probably could stand the squeeze.).

Consequently, a wing failure with a neoprene drysuit is no different that with a shell type dry suit. I know. I have practiced that evolution at depth in both types of suits. Do not confuse the limitations of a neoprene wet suit with a neoprene drysuit where you can add air - just like any other drysuit.

With either type of suit you crank the exhaust valve closed to allow more air to be held in the suit and you then inflate and use the suit for redundant bouyancy during the ascent. Even with a snug fitting neoprene suit, you can pump a lot of air in them becuase the material stretches. As you ascend, you vent the suit as needed and can then stop at the deco/safety stop(s). It is really no differnent in that regard than a trilam.

I cannot think of any technical diving situation where you would want to or ever need to dump weights except may be at the surface to establish additional bouyancy. Deco diving and dumping weights are just not compatible with each other.

I do find a neoprene drysuit to be more ammenable to unusual attitudes as they do not tend to allow excess air to rush to your feet if you are head down as will potentially happen even in a well squeezed trilam suit. I used to have to carefully contemplate and preplan getting into head down positions in a trilam but I don't have to give it a second thought with a neoprene drysuit. They really do swim better than a shell suit in every regard.

Just a thought, but how about we add some weight to our opinions from this point forward and actually mention whether we have dove both either one or the other or both types of suits. It will help cut through the dogma, speculation, misinformation and "I heard somebody say that" comments on the subject.