Likelihood of getting oxygen toxicity at 1.4 PPO

[kelemvor]

So how does that work for OOG?

It appears that you have to remove the whole mask to take gas from a donor and carry an additional normal mask?

As I said there are a number of options.
1. Remove FFM and put standard reg from alternate source in your mouth.
2. If you're carrying your own alternate gas source, you can have it connected to a second port on the mask.
3. If you're carrying your own alternate gas source, put a QD on the LP hose.
4. You could utilize a gas switch block.

Personally, I go with option 1. It's easy and cheap. If I were solo diving more, I might use a pony with a QD on the LP hose. If you put a "normal" second stage on the QD then you could use it to hand off to a non FFM diver OR just remove it and connect to your own mask.

 

[RainPilot]

Not lurking really but here is the KM48

View attachment 462792

Thats the Mod-1, I have several of the cheaper Supermasks I use for comms and CCR diving.

Was that on your IWR course?

 

[Searcaigh]

KM48 has a pod with the reg and it can be easily removed to allow another regulator to be used

 

[Searcaigh]

Was that on your IWR course?

Yes, we also had a ScubaPro mask but those who used it found that it did not seal as well as the KM

 

[RainPilot]

The Supermask is the same, a lot lighter though. Also half the price.

 

[Searcaigh]

And to get back onto the subject

IIRC this was after 15mins on 100% at 9m then an air break for 15 min followed by 100% at 7m for 20 mins and no tox

 

[JVos]

Back a few years when I started cave diving, the common gas was 32%. A few divers had some problems and suddenly everyone was banking 30%

 

[tbone1004]

Back a few years when I started cave diving, the common gas was 32%. A few divers had some problems and suddenly everyone was banking 30%

who's "everyone" banking 30%? I know of some that do, but 32 is still more common that I see....

 

[Storker]

Aren't full face masks and deco on 100% somewhat beyond basic scuba?

 

[BRT]

I have a dim memory that I read somewhere that in "the good old days" they had a recommended limit of 2 or 2.1. Later on when understanding get better and risk awarnes rise, the limit was altered to 1.6 and now 1.4

I would not do a dive on 2 or even 1.6, but i see no problem planning a dive to 30 meters on 32%, and a MOD on 32m, PPO2 1.4. But it is then important to keep control on my depth so I don't go down to deep.

There are always a probability of oxtox when PPO2 rises, but I think that if I keep under 1.4 the probability is so small that it is close to zero. There are some safety marginal already in the recommendations.

Would you be willing to drop to 130 for a couple of minutes during a dive on 32%?