I think WetSuits are Safer and Better than Dry suits for the vast majority of divers

[thez_yo]

Heated undergarments may have some significant risks associated with them. It was very clear from Neal Pollock's presentation at DEMA that, if you use a heated UG from the beginning of your dive and run out of battery before you ascend, you will have significantly increased your DCS risk.

Could you elaborate on that, please? I regularly dive a heater and 5mm wetsuit here, to keep my amount of lead down primarily because of a back injury.

 

[victorzamora]

I didn't hear the talk, but I believe I understand. If you're diving with an electric heater that goes out, you'll have less exposure protection than otherwise "required" for those conditions. If this happens before the end of your dive, you will find yourself in the water, severely under-dressed for the temperature. This could lead to hypothermia, increasing your chances for DCS. Lynne, please correct me if I'm wrong.

 

[GrumpyOldGuy]

I would have 2 concerns to address before I replace my d/s with a heater.
1) Will it last all day for 3-4 dives including surface intervals?
2) Am I 100% positive the battery is not going to fry and burn me in a failure mode?

Other than that, its a great idea and being able to control the heat is a bonus. I prefer a wet suite over a dry suit any time I don't risk freezing my butt off, typically multiple dives in winter. My dry suit has multiple failure modes, but only one (stuck inflation valve) has a serious risk and that can be addressed. The power pack in a LI battery pack can do significant damage.

 

[mmadiver]

Utility over fashion, which is why I dive dry. My Drysuit enables standardization of my diving that can be applied to many environments by simply changing undergarments. My drysuit pockets will always be there, with my standard loadout, if I’m diving in 30 degree water or 75 degree water.

I do sympathize with the OP to a certain extent.
Diving is a commercialized sport and as such many divers choose fashion over utility - a lot of rec. divers are under the impression that a drysuit is a requirement to be among the “elite”.

 

[Dr. Lecter]

Heated undergarments may have some significant risks associated with them. It was very clear from Neal Pollock's presentation at DEMA that, if you use a heated UG from the beginning of your dive and run out of battery before you ascend, you will have significantly increased your DCS risk.

I think I know the answer to this already, but did he mention any risks with not using it at depth but kicking on the heat for the last 1/2 to 2/3 or so of the deco hang? I would think it would actually up your deco efficiency quite a bit. I was fine this past weekend on the bottom at 270' in a lavacore shirt and dive trunks, despite the thermocline, but deco was another matter and I would dearly love to have a heated shirt I could turn on for the hang without to go through the trouble of diving a drysuit in HI.

I didn't hear the talk, but I believe I understand. If you're diving with an electric heater that goes out, you'll have less exposure protection than otherwise "required" for those conditions. If this happens before the end of your dive, you will find yourself in the water, severely under-dressed for the temperature. This could lead to hypothermia, increasing your chances for DCS. Lynne, please correct me if I'm wrong.

The other problem as I understand it is that increased body temp equates to increased tissue perfusion and therefore increased gas loading/unloading. If you're warm on the bottom, you're going to uptake more gas than you otherwise would. Not a problem, as long as you're equally well-perfused on the way back up. But if you're cold, you'll be offgassing much more slowly.

 

[elan]

If I had a chance I would only dive a wetsuit.

 

[TSandM]

The study Dr. Pollock reviewed for us showed significant utility to being warmer on deco. His point, and it is a good one, is that if you PLAN your NDLs to take advantage of that, you are in a world of hurt if, for some reason, the heated garment fails to function. Similarly, if you run the garment during the entire dive, you have a problem if it fails at some point.

The concept is that being warmer causes increased nitrogen uptake because it causes increased tissue perfusion in the skin and extremities. If you go from warm to cold, you are most efficiently absorbing nitrogen, and far less efficiently eliminating it.

 

[Tigerman]

If I had a chance I would only dive a wetsuit.

Me too. A 2.5mm shorty if I could choose...
However thats just not how the world works. If I want to dive more than 3 months a year plus a couple of vacations, its time to go dry. So I actually didnt even OWN a wetsuit for the first 6 years I was diving - it was a redundant waste of space. The only reason I got one was because I got it cheaper than a single dive trip worth of renting (and less importantly because nobody ever pissed in it)

 

[dumpsterDiver]

The study Dr. Pollock reviewed for us showed significant utility to being warmer on deco. His point, and it is a good one, is that if you PLAN your NDLs to take advantage of that, you are in a world of hurt if, for some reason, the heated garment fails to function. Similarly, if you run the garment during the entire dive, you have a problem if it fails at some point.

The concept is that being warmer causes increased nitrogen uptake because it causes increased tissue perfusion in the skin and extremities. If you go from warm to cold, you are most efficiently absorbing nitrogen, and far less efficiently eliminating it.

Of course a dry suit COULD get punctured or flood and then have you freezing on deco, while a typical wetsuit, would loose little thermal protection from a small hole suffered during the dive, particularly since the wetsuit will be expanded and provide insulation on deco.

So it is better to be cold at depth and warm on the hang....?? that sounds like a wetsuit to me..

 

[boulderjohn]

Whether one is in a wet suit or a dry suit, the tendency is to be warmer on the dive than during deco. For the reasons Lynne noted, that is less than ideal, but that is the way it frequently happens. A decompression dive can be a very long affair. The diver is more likely to be working during the deep part of the dive than during the decompression stop. In addition we tend to get colder as the dive progresses, whether in a wet suit or a dry suit.

A couple of years ago I did a number of decompression dives in Florida with the same group of people. They were in wet suits. On several occasions during the decompression, they would indicate that they were getting very cold. I was in a dry suit with just light underwear, and I would sometimes intentionally irritate them by indicating that I was nice and warm. I was cooler than I was earlier on the dive, but I was definitely warmer than they were.

The next two years I dived with them again. Funny thing--they were all wearing dry suits.