80cu Tank at 800 Feet ????

[UCFKnightDiver]

with a mix containing .06 of oxygen would keep your pp02 levels safe at that depth right ?

Sounds about right. 1.4/25ata=.056O2

 

[speedyal]

Define "safe."

There are also more things to take into consideration than just your PO2 levels longgggggg before you'd hit that depth.

List them if you would please

 

[speedyal]

Sounds about right. 1.4/25ata=.056O2

Thanks man

 

[Rhone Man]

How long can you breath of a 80cu tank at like a luxfer al 80 at 800 feet also whats the formula for figuring this out heres what i got

800 divided by 33 = 24

80cu divided by 24 = 3cu

on google i found something that said the average person breaths a quarter of a cu every breath

so based on this i determined at 800 feet a tank would last 12 minutes but that just doesnt seem correct so tell me what im forgetting or messing up on

Your maths looks right, but your units are wrong - 3 cu ft divided by 0.25 cu ft per breath means you get 12 breaths - not 12 minutes!

But I suspect that figure may be on the high side. I remember reading that when Nuno Gomes set his world record at 1,000+ feet, that an Aluminium 80 would only last 3 breaths at that depth.

But bear in mind that (i) every person consumes gas at different rates, and (ii) ultra deep divers usually breathe extremely slowly and have very low heart rates. I also remember reading that when Bret Gilliam set some world record or other, he was only taking one breath every 26 seconds or so.

 

[speedyal]

what would be your first deco stop at this depth

 

[Rhone Man]

Define "safe."

There are also more things to take into consideration than just your PO2 levels longgggggg before you'd hit that depth.

List them if you would please

I'll take a shot at this if you like:

• narcosis - even breathing a pure heliox mixture, you are going to have a pretty monstrous EAD
• breathing resistance - again, even breathing pure heliox that would be the equivalent of breathing air at about 300 feet
• C02 retention - killed David Shaw
• HPNS
• and of course, everyone's favourite - decompression obligations. Count on at least 7 or 8 hours of deco for a trip to that depth, even on a bounce dive.

 

[Cave Diver]

I'll take a shot at this if you like:

• narcosis - even breathing a pure heliox mixture, you are going to have a pretty monstrous EAD
• breathing resistance - again, even breathing pure heliox that would be the equivalent of breathing air at about 300 feet
• C02 retention - killed David Shaw
• HPNS
• and of course, everyone's favourite - decompression obligations. Count on at least 7 or 8 hours of deco for a trip to that depth, even on a bounce dive.

That pretty well nails most of the ones off the top of my list. Also .06 O2 percentage gives a PO2 of 1.5 Personally, if I was diving to even half that depth I'd want to knock several tenths off of that PO2.

Not to mention the logistical support for other divers and equipment necessary to pull off a dive to to that depth.

 

[speedyal]

anyone know what the deco stops for a dive like that would look like ? how many how long and what depth and thanks rhone man and cave diver for all the info

 

[Cave Diver]

what would be your first deco stop at this depth

~700'

 

[Cave Diver]

anyone know what the deco stops for a dive like that would look like ? how many how long and what depth and thanks rhone man and cave diver for all the info

Yes.

But for obvious reasons I won't post any more detailed deco information than we've already given. Never know when someone might just be crazy enough to try it after reading about it on the internet.