Cousteau Britannic Expedition?

[phsdive]

I believe that I read Cousteau's team used Heliox and was pretty cutting edge for its time. By my calc's, at 400 feet (125 metres) o2 would be around the 10% mark and hypoxic. This thread made me think about their set up what o2 level did they dive with and if they used travel gas to reach a level where the lower o2 level would safely support a diver. Anyone know? These guys were amazing divers and their efforts ad techniques should be remembered.

[Ron]

It does raise some interesting questions, doesn't it? What a cool documentary. Keep in mind that people used oxygen to upwards of 2 atmospheres absolute of pressure back then. Cousteau himself almost died using oxygen rebreathers way deeper than what would be considered even a contingency depth today, commercial divers and oxygen tolerance testing notwithstanding. I watched the whole thing, and they only used royal mistrals with extended hoses and those triple tanks that Ryan mentioned earlier. It appears that one of the tanks was acting as a reserve, and the other two were for bottom time. They were doing some long decos though to have to lock into a chamber at 150 feet to do the rest of their deco on the surface with oxygen. I'd love to learn more as well. 400 feet with only a doublehose and no pressure gauge.

[Greg Barlow]

As I was watching the Britanic episode again, I noticed that the cans had been rotated so that the intake hose came over the divers' left shoulders. You can clearly see the configuration beginning at 34:30. What caught my eye was the upside down label.

Interesting....

[Superlite]

I haven't done the calculations but I'm guessing Cousteau used a 95/05 mix in the Britannic dives. 10% oxygen would be to much. I've made dives on a 95/05 but we did a switch at 100ft from air to HeO2. Then switched back to air at 150ft for deco. Also due to heat conductivity of HeO2 I have a hard time understanding why JYC would use a knit hat other than "showmanship". A towel and knit hat would offer no warmth at depth. Anyone diving to 400ft would be awfully cold upon reaching the SDC at 150ft. But upon entering SDC you would warm up somewhat due to mix change of HeO2 to air. Or some other deco mix.

[phsdive]

Superlite, 10% 02 is the number I think. Would give you a pp of about 1.4 at 125 metres. Would love to see the dive plan they used (travel gas, bottom mix, deco etc...)