Diving deep and cold

A while back there was some discussion about the dangers of diving deep and/or cold with a wetsuit and steel. I've searched and can't find the thread. Could someone point me in the right direction or summarize the dangers of the scenario.
Thanks,
David

The danger is when your wetsuit compresses, and loses its inherent buoyancy, then you will be compensating for a lot of weight with your BC. If your BC fails, you might be so negative you're stuck on the bottom.

This is usually not a problem unless you are diving double steels.

Do a search for "balanced rig" or "double steel wetsuit" That should give you reading material for days.

Tom

+1

A single steel tank is not as much of a problem with a wetsuit. No worries.

A set of double steel tanks is just unwise with a wetsuit, for the reasons above.

(If you're requiring a set of large double steels for your diving, there is a good chance that your exposure durations would make it wise to use a drysuit anyway.

Being hypothermic and still having another 25 minutes of deco to perform is a really peculiar form of self-torture to inflict on yourself...)

Are those yellow first stages Doc?

They have that yellow and green Mk 20 Nitrox trim package look to them.

You got it, Toyota! They're a pair of Mk 20's from somewhere around 2002 or so that were SP's answer to the "Nitrox Regulator" craze - they had green and yellow polymer covers on them.

Larry, didn't they also have a couple coatings or pieces in the inside that were supposedly 'special' as well? I forget...

Anyway, they work well. I have three Mk 20s and one Mk 15, and a couple Mk 10s that I use on the 70' and 20' bottles. I like old SP regs.



Doc

The issue with diving a wetsuit and a steel tank is that if you were to have a catastrophic wing failure at depth at the start of your dive, you might be massively over weighted and unable to get to the surface.

If you can go down deep enough to have significant suit compression (say 100 feet), with a full tank, and still swim your rig up with no aid from your wing, you should have no problem diving with a steel tank and a wetsuit. When I first got my HP130, I took it out and dropped to 90+ feet, had my buddy make sure I had no air left in my wing, and tried to swim it, plus some extra weight, up. I had no issues swimming it up to 50 feet (where my suit was significantly less compressed and swimming it up was no longer difficult at all), and thus diving with a steel tank and my wetsuit is fine for me.

If you find that you cannot swim your entire rig up, but you could if you had X pounds less, you can use that much as ditchable weight, and then you should still be fine diving in the steel. But beware that by ditching weight, you will be inherently very positive when you are shallow and your suit is no longer compressed....you may run into issues of not being able to maintain a safety stop, so your best bet would be to dive dry, that way you have the redundant buoyancy compensation.

That's what I thought I remembered seeing. Issue #1 is can you swim your rig back up. Issue #2being if you ditch weight to swim it up, you risk an uncontrollable ascent.

Guys....when people are threatening you with impending doom for diving wetsuits with steel tanks, they're talking about 2 of them - a set of double steel tanks. Not one single tank, no matter what its made of.

I'm not familiar with anyone on the board going around warning divers they're going to die if they use a single steel tank with a wetsuit. Divers who cannot dive in a wetsuit with a single steel tank need to take up golf. The only thing a single steel tank does for a wetsuit diver is take some lead off their weightbelt.

Take what you hear on the internet generally and SB specifically with a grain or two of salt.

Regards,

Doc

Doc, you have seen Nereas' posts, right? He's always warning people of impending death when you mix wetsuits and steel tanks....regardless of buoyancy characteristics of the tank or the thickness of the wetsuit. Life according to Nereas: wetsuit + steel tank = certain death

But yes, you are absolutely correct....a single steel tank (even an HP130) with a wetsuit (even a 7mm farmer john) will not cause any more problems than an Al80 and a 3mm wetsuit, provided you know what you're doing.