Undergarment

[FreediveWI]

I never thought about it. A single steel tank and a steel back plate are all that I ever use.

Jon

[john j]

For our long deep dives, we are using electric heat in addition to our undergarments. Check out . They have submersible heating pads that you can wear inside a wetsuit or drysuit. The system we use is a bit more elaborate than that, but the idea is the same and it is based from patco components. If you can get some active component that is adding heat to your body, it makes a huge difference. Since I've started using heaters, I can't believe I could have ever done these types of dives without it. Now, I'm actually toasty warm on most of these dives, even after 2-3 hours of deco. System is not cheap, but it really works great and for about $1000 you can get a good set-up. This is still way less expensive than the DUI heater system was however. If you were ice diving, you could have a wire leading up to the surface and you wouldn't need the underwater battery pack. That would save you hundreds of dollars becasue the high capactiy battery pack is the most expensive part. You could run it from a car battery since it is all 12 volts. That would be slick and it would keep you warm all day. My battery pack lasts a bit longer than 2.5 hours if used continuously. Patco has lots of different battery sizes too. You should go with the nickel metal hydride batteries if you go this route. They don't show that stuff on their website and you have to ask about it. The lead acid packs they show on the web won't cut it up here in the north land.

[FreediveWI]

John,

It sounds like you have had a lot better luck with yours than I did with one that I bought about 10 years ago.

Mine was about $400 back then and had a seperate battery pack and thermostat. It went into my suit through a plug and would heat up one spot at a time.

It worked out OK as a wetsuit heater, but I never had much luck with it as a drysuit heater. For wetsuit use I would wear it down in hte spine area of my wetsuit. that way everytime I would move around warm water would get squeezed out of that pocket and into the rest of the suit. For drysuit use I wore the pad on my belly and it would just warm up that one spot, but nothing else.

I know that Greg Zamebeck used to use electric motorcycle underwear under his drysuit. He had it rigged to a DiveRite neutralight cansiter and even had made gloves that would hook into the system.

In the end, my thermostat unit went out and the company went out of buisness. After that I just stuck with thinsulate and argon.

Jon

[dfreeman]

I have seen this rig and it looks good. Expensive but nice. I think that the set up was very nice.

Doug

[john j]

I can honestly say that the system we have worked out is nice and I don't have any serious problems with it. It's not perfect, but overall I'd say it's one of the more reliable pieces of gear I have. The only drawback is that it is quite expensive.

I initially started with a 50 watt pad on my chest under my drysuit. That cranked out so much heat that it would sometimes burn me. I am not using a thermostat, just on/off control, which is fine for me but I could see that some other people might want a thermostat. The on/off switch is easy to reach and it's simple. Now I have a heated jacket that has heat all around, even in the arms and neck. The heat is not as intense as the pad, but it totally surrounds my upper body and feels really nice. I have gloves and socks that plug into the jacket too, but I find that I only need them in very early spring when the water is at its coldest. Of course, the more stuff I have plugged in, the faster the battery dies. With just the jacket, I get about 2.5 hours of continuous use from my onboard battery which is 13.5 amp-hours. This battery is roughly the size of an OMS 13 ft3 argon bottle without the valve. This year, we have added underwater pluggable connectors so we can have a battery hanging on the deco line or whatever and plug into it if we need to on really long decos. You can also get a larger battery pack from Patco and then you wouldn't need the underwater pluggable connectors, but the high capacity batteries are not cheap. Of course, with the U/W connectors, if my main battery floods, I could plug into another one and still get heat. For the batteries that we hang on the deco line, we can use the cheap sealed lead-acid variety which will save hundreds of dollars.

Of course, I still use really good drysuit underwear and I'm not relying on the electric heat 100% becasue it could fail. In reality though, for me personally it would not be realistic to attempt these really long dives without some kind of active heating device. I get cold very easy compared to most people I dive with.

[Omicron]

That sounds neat, but still pretty expensive. Has anyone tried those little disposable handwarmers before? They make ones that have a sticky back so you can just stick them on somewhere. I've used them hunting and at packer games, but i've always been curious if they would work in my drysuit or not. Stick one on my chest, one on my lower back and get a couple of the foot warmers for my toes.

I was thinking of trying it out this weekend and seeing how they worked. I just don't know if there would be enough air in the suit for them to function properly.

[FreediveWI]

The unit I had, made by a company called Repetative Diver, didn't have an option of not using the thermostat.

I like the idea of hanging the battery at your deco stop. We used to do somthing similar to this back in the days of Canadian Navy tables, instead of deep stops. I would hang my argon bottle at 20', where the 02 hooka regs were stationed, and even have some extra weights waiting there that I could clip onto my harness. When I got to the 20' stop, the longest since I did all the hanging at 20' and none at 10', I would clip those extra weights on myslef and really pump up my suit with the argon to make the long hangs more enjoyable.

Of course, now with deep stops, and gas deco tables, my whole deco time is shorter than my 20' air stops where back then. ;D

Another neat toy I saw that greg Zambeck had made was a portable water heater that he would drag out onto the ice when doing his 300' ice dives up in Wazze. He had 300' of garden hose pumping 150 degree water down to him. If a reg would start to freeze he could just flush it with hot water while at depth. If his hands got cold he could just puth them under the hose and the warm water would heat them up right through the dry gloves. The heater assembely was pretty big, but still a cool set-up for some extreme ice dives. I think I have a picture of it around here somewhere. ???

Jon

[john j]

I have tried them and found that they don't work too well. They need oxygen to work and if you are using Ar to fill the suit, they fizzle out pretty fast. You can get the gel-pack kind that are re-usable though and they do work. You have to microwave them or boil them in water which dissolves the crystals inside making them ready for use. When you want to use them, you press on a metal tab inside the gel-pack and it starts to get hot and lasts for a while. You can then microwave them again to re-dissolve the crystals and they are ready to use again later.

Give your idea a try, but when I did that, it didn't work all that well.

[FreediveWI]

I agree with John on this.
Before we started using argon in our drysuits we would put the handwarmwers inside our drygloves on the back side of our hands- where all the blood vesseles are. We found out that you really need to wear them with two thin liners and put the warmer inbetween the two- not right on your skin where they can too hot. They worked out ok that way, but not as well as argon. Once you switch to argon they are no longer effective because of the reason John gave.

jon

[Omicron]

Thanks for the tip on those gel pads - I'm searching around for some of those right now...

I can see how the regular pads wouldn't work using argon - no oxygen....

Maybe they'd work better on nitrox ;D