scuba diving deeper than 300 feet

[H2Andy]

Is this what happened to Dave Shaw at Bushman's Hole?

he way overworked himself at depth (over 800 feet) and started hyperventilating, passed out from CO2 buildup, and drowned

lack of mental clarity due to narcosis certainly contributed to the death (he was on a CCR)

 

[drbill]

At that point it becomes decompression and density of the breathing media, I think heliox can go to 1500 to 2000 feet and then you start using hydrogen oxygen mixes (COMEX played with this).

You mean they just put water in the tank and dissassociate the H and O? Just teasing, just teasing.

 

[Hallmac]

Navy standards were for a max depth of 297' on air and a max WORKING depth of 150 on air in SCUBA. .

Remember the rule regarding Navy tables and it makes all the difference.

U.S. Navy rule.

(1) The maximum recommended depth for a particular situation that must be
completed without failure.

(2) Return to surface is optional.

(3) A reusable diver is a bonus not the rule.

If your diving fits into the above then it is all good.

 

[Gene_Hobbs]

At that point it becomes decompression and density of the breathing media, I think heliox can go to 1500 to 2000 feet and then you start using hydrogen oxygen mixes (COMEX played with this).

Trimix is needed to go that deep (COMEX and Duke 'Atlantis' Dives). HPNS sx are too much in that range.

Fun read:
Brauer RW (ed). Hydrogen as a Diving Gas. 33rd Undersea and Hyperbaric Medical Society Workshop. UHMS Publication Number 69(WS-HYD)3-1-87. Bethesda: Undersea and Hyperbaric Medical Society; 1985; 336 pages.

More workshops listed here.

 

[H2Andy]

(1) The maximum recommended depth for a particular situation that must be completed without failure.

check ... i think (is that in English?)

(2) Return to surface is optional.

oh hell no ... my buddy gets to use this table

(3) A reusable diver is a bonus not the rule.

hahaha ... so long i come back, don't care what happens to my buddy ... check

 

[rakkis]

That's amazing. H2 and O2 under high pressure in a metal enclosure. Makes me nervous just thinking about it.

Really? it makes me giggle

 

[mobster75]

A more insidious problem even before you get to Oxtox levels is the Dark Narc: Deep Air with increased Gas Density & Work-of-Breathing; then throw in Physical Exertion or a Stress Condition, resulting in overbreathing the regulator --all leading to the Vicious Cycle of CO2 Retention and sudden Narcosis. Can result in severe cognitive impairment at depth or worst case stupor and ultimately unconsciousness. . .

Been there... Done that... It sucked....

 

[Gary D.]

Remember the rule regarding Navy tables and it makes all the difference.

U.S. Navy rule.

(1) The maximum recommended depth for a particular situation that must be
completed without failure.

(2) Return to surface is optional.

(3) A reusable diver is a bonus not the rule.

If your diving fits into the above then it is all good.

I have heard a similar one and some think it’s serious, but in all reality it's a joke. The Navy did and does a good job at keeping divers surfacing and returning safely.

One of the biggest differences between the tables is they ARE safe for people in good to great physical condition like most military divers are. Where they become dangerous is for the couch potato whose extent of physical activity is using two fingers to operate a remote control and the other three to hold the beer.

Like a lot of other stuff in this sport. If the majority of people can’t pass something lower the standards so they can.

Gary D.

 

[hokie_diver]

Really? it makes me giggle

Well... to each his/her own. :14:

 

[Thalassamania]

You and me both. They can't use more than 4% O2 or it will combust as is my understanding. Either way, no thanks.

It's not a big deal, low hydrogen percentages in air brought out over platinum wool in the intermediate pressure line was used by divers at Scripps to warm and humidify their breathing mix.