Who is riding trimix dil all the way to the surface and who is flushing to a nitrox dil?

[bubblemonkey2]

What?

What is the "What?"

If you are on a CCR--at the surface--the minimum percentage of oxygen in the loop to avoid having to worry about hypoxia is--OFFICIALLY--40%. A.k.a. a ppO2 of 0.4. But 70% is safer. And you can easily abide by this on hypoxic diluent, or even a pure helium diluent, by maintaining setpoint.

Some agencies/manufacturers even want you doing a routine 100% O2 flush at the surface, because of prior drowning incidents.

Possibly counter-intuitive for people who are thinking about numbers for minimum survivable open air & OC mixes.

 

[mr_v]

What is the "What?"

If you are on a CCR--at the surface--the minimum percentage of oxygen in the loop to avoid having to worry about hypoxia is--OFFICIALLY--40%. A.k.a. a ppO2 of 0.4. But 70% is safer. And you can easily abide by this on hypoxic diluent, or even a pure helium diluent, by maintaining setpoint.

Some agencies/manufacturers even want you doing a routine 100% O2 flush at the surface, because of prior drowning incidents.

Possibly counter-intuitive for people who are thinking about numbers for minimum survivable open air & OC mixes.

This is way more coherent than the original post. Thank you.