Unpressurised Dry Suit for Shallow Surface Supplied Air Diving

[Imla]

Also keep in mind that a lot of the warmth in using a dry-suit comes from the volume of air insulating between body and water. So one thing is diving with squeeze and the pain it causes. Another is that the dry-suit wouldn't really be very effective. I'd rather go for a proper nice open-cell wet suit or something.

 

[Edward3c]

I think you’ve gathered using a drysuit without a means of balancing the ambient pressure isn’t a good idea.

You’ve now introduced another poor idea, the Spare Air. Even if you’ve got the 300 series you still only have 85Lt of free air; with the 170 you get 45Lt. Using the BSAC 25LtMin for gas planning you would have less than 2 minutes at 10m and about 1 minute at 20m.

The Spare Air is a joke for a scuba bailout, get at least a 3Lt pony (600Lt free air at 200bar) with a proper reg – they cost a little bit more, but give you time to sort out problems - remember you could get tangled by your surface supply..

 

[Outbound]

Not to mention the crotch squeeze.

Exactly. Do one dive where you take a suit squeeze in the nutsack and you'll never dive with a squeeze again.

 

[Searcaigh]

and my spare air with a hand pump every so often, but refilling a regularly used drysuit tank with a hand pump is a lot more time consuming in the middle of a shoot on location.

A hand pump

I'm guessing you've never tried to pump to 200 bar.

 

[Kendall Raine]

You’ve now introduced another poor idea, the Spare Air.

The Spare Air is a joke for a scuba bailout, get at least a 3Lt pony (600Lt free air at 200bar) with a proper reg – they cost a little bit more, but give you time to sort out problems - remember you could get tangled by your surface supply..

Exactly right. The Spare Air is a perfect example of mindless dive industry "innovation." That is, taking a HEED bottle intended for emergency helicopter egress and turning it into an "alternative air source" sold to people too ignorant to know better.

 

[OTF]

What's wrong with a spare air for this use case? Shallow water. Way better than nothing.

Agree a bigger pony is better and allows him to inflate the suit too. But it sounds like maybe he has no access to air fills.

 

[ScubaBunga]

It's been 20+ years since I did a dry suit dive - are there any "manual" inflation options for a drysuit - i.e. breath in and use whatever hose/adaptor to then breath air into the drysuit like a manual bcd inflation? Probably get some water in that way - but maybe that would be acceptable if there is such a thing.
(I agree with the small pony bottle for inflation - but was just wondering)

 

[formernuke]

What's wrong with a spare air for this use case? Shallow water. Way better than nothing.

Agree a bigger pony is better and allows him to inflate the suit too. But it sounds like maybe he has no access to air fills.

Spare air at anything below about 10ft is worthless.

 

[Kendall Raine]

What's wrong with a spare air for this use case? Shallow water. Way better than nothing.

Agree a bigger pony is better and allows him to inflate the suit too. But it sounds like maybe he has no access to air fills.

If no access to air fills then how to fill the Spare Air?

Agreed Spare Air could get you to the surface from 30', depending on the model. But that is missing the forest for the trees. This whole thread is a compilation of special case hacks trying to get around just doing this in a thoughtful way-like using suit inflation gas/proper bailout.

 

[Orthodoxality]

OK great points. I was using "spare air" generically, but the bottle I've got isn't much better, and I certainly haven't tried hand-pumping it all the way to 200 bar yet!
I guess I've been thinking about this as "snorkelling, but without the need to surface!" instead of "SCUBA, but without the ability to go very far or deep or in bad weather", but that's a great point about getting tangled in the hose. If I somehow managed to tangle myself up in it and pull it out, I'd be in pretty big trouble very quickly.

I could probably fit something like the MiniComp MiniDive [1] in the van. With a couple of cycles, it could pressurise a 3 litre pony bottle to keep in reserve, and a 1 litre dry suit bottle for every dive.

Does this sound like a workable solution? I really appreciate everyone's input to the newb, and apologize for being so blasé about this. I wasn't treating 12m of water with the respect it clearly deserves.
A big part of the ultimate goal is the desire to be able to operate off-grid for extended periods using a solar generator. I've been able to do this for a lot of other stuff, but it does involve a lot of "special case hacks", as does my entire life!

[1] Compressor MiniComp MiniDive