An age-old question: ways to 60m.

[steinbil]

Air to 70m is beyond the 1.6 ppo2 that many equate to a safe limit, narcossis not withstanding. What we're saying is make your own choice for your own diving, but don't berate and belittle those that choose a different path.

Funny how you arbitrarily choose to stick to the recommended limit of 1.6ppO2, but completely disregard the recommended maximum limit of 6.2g/L for gas density. Especially considering the latter affects the risk of the first.

Also, no one really cares what stupid and unnecessary risks deep air divers expose themselves to, but bragging about it or recommending others do the same will of course be met with resistance and/or ridicule.

 

[bardass]

.

 

[bardass]

Good on you mate. If you are irresponsible then the following world class organisations must also be irresponsible in relation to max air diving depth:
BSAC 50 m
IANTD 57 m
TDI 55 m
IEG 56 m
RAID 56 m

USN 57-66 m
RN 50-60 m
RAN 50-60 m

In stark contrast:
GUE 30 m, although I have dived with GUE guys who have set their equivalent narcotic depth at 20 m with Trimix.
UTD 39 m

FFESSM, ANMP, FSGT (France) : 60 m
LIFRAS, ADIP (Belgique) : 60 m
SAA (UK) : 50 m

 

[jborg]

Good on you mate. If you are irresponsible then the following world class organisations must also be irresponsible in relation to max air diving depth:
BSAC 50 m

"BSAC recommends choosing a gas that gives you an equivalent narcotic depth of 30m or less"
(Safe diving guide)

Se linked tables etc recommending adding helium for 35m and deeper. "World class organisations" are shifting their stance on this, and the direction is clear I think.

IANTD's course program is a mess and who knows (or cares) what they recommend, there's a "recreational trimix diver" course qualifying you for no-stop dives using trimix in the 30-40m range only (Recreational Trimix Diver), for example, in addition to their deep air stuff.

RAID... I don't know what RAID thinks. There's the "Deco 40" course, which teaches you to:

• Use any optional combination of air, nitrox, trimix and / or oxygen (optional Trimix)
• Complete a maximum of 10 minutes' decompression.
• When completing a decompression dive, divers must use a bailout gas.
• This bailout gas must be safe to breathe at the maximum operating depth of the decompression dive.
• If this gas is different from the primary breathing gas, divers must use a multi-gas switch computer and perform no-decompression dives.
• Certify to use up to 100% oxygen to extend their no decompression dive times by using multi-level gas switch dive procedures.

(Deco 40 – Dive RAID International)

I challenge anyone to explain what that's supposed to mean and how it represents a serious, world-class approach to safe diving...

 

[Blackcrusader]

"BSAC recommends choosing a gas that gives you an equivalent narcotic depth of 30m or less"
(Safe diving guide)

Se linked tables etc recommending adding helium for 35m and deeper. "World class organisations" are shifting their stance on this, and the direction is clear I think.

IANTD's course program is a mess and who knows (or cares) what they recommend, there's a "recreational trimix diver" course qualifying you for no-stop dives using trimix in the 30-40m range only, for example, in addition to their deep air stuff.

FROM BSAC

• If you are diving deep, then you should consider using trimix to reduce the effects of narcosis and improve work of breathing. BSAC recommends choosing a gas that gives you an equivalent narcotic depth of 30m or less, especially if you are undertaking a complex dive. However, a high level of helium can also increase the amount of decompression time some algorithms ask you to do, which can add other risks. You need to plan your dive carefully taking into consideration the risks and choose an appropriate gas for your plan.

 

[iliketopetsharks]

FROM BSAC

• If you are diving deep, then you should consider using trimix to reduce the effects of narcosis and improve work of breathing. BSAC recommends choosing a gas that gives you an equivalent narcotic depth of 30m or less, especially if you are undertaking a complex dive. However, a high level of helium can also increase the amount of decompression time some algorithms ask you to do, which can add other risks. You need to plan your dive carefully taking into consideration the risks and choose an appropriate gas for your plan.

Outdated and irrelevant

 

[Blackcrusader]

Outdated and irrelevant

BSAC or Helium?

 

[iliketopetsharks]

BSAC or Helium?

The section you've highlighted. And deep air.

 

[harvalen]

Weird that BSAC would set a maximum upper limit for helium content based on depth. As if having 55% helium is somehow worse than 50%. I wonder if they still believe the old "helium penalty" myth about decompression?

TDI has something similar, with max 35% helium for helitrox ccr diver, TDI CCR Helitrox Decompression Procedures

My guess is that it's a way to make it harder for people to get gas mixes for dives that exceeds their training. Maybe it will stop the subset of people that still care about gas density even though they are otherwise fine with going deeper than they are trained for, the rest will likely just dive with a gas that is too dense.

 

[rddvet]

I think we need to rename this thread to Dunning-Kreuger in real time. If you dive deep air and don’t know what the dunning-kreuger effect is, you may want to do some research.