Sealab

[luis]

Here is a great video:

http://www.youtube.com/watch?v=B_dELsrvYGw

[Popeye]

Good find, I like the film titled "Secret Navy Undersea Colony Revealed! - The Story of Sealab I"

[SurfLung]

- Thanks for that link. I've been wondering about Sea Lab for the past two years since I got interested in Vintage diving. Got the World Without Sun video and it seemed that Cousteau went from diving innovation into environmental pursuits and TV without looking back. Last month's Historical Diving Society magazine had a great article on COMEX and the deep (almost 2,000 ft if I read it right) saturation diving they pioneered for work in the oil industry.
- This Sea Lab movie is great. It looks like the habitat divers were using some sort of re-breather... But I did see bubbles either exhaling or escaping. And, I saw more than a few AquaLung logos and familiar open circuit vintage equipment.
- 80% Helium, 16% Nitrogen, and only 4% Oxygen... I wonder how they figured out that specific mixture... I always thought they just went 80/20 He/O2 to replace the Nitrogen.

[luis]

-

- 80% Helium, 16% Nitrogen, and only 4% Oxygen... I wonder how they figured out that specific mixture... I always thought they just went 80/20 He/O2 to replace the Nitrogen.

At 200 feet (about 7 atm absolute) the 4% gives you a partial pressure of 0.28 atm. This is more O2 than you at the surface.

Using a gas mixture with 20% O2 would give you an O2 partial pressure of 1.4 atm.
That would be toxic in a relatively short period of time. It would give you CNS (central nervous system) O2 toxicity and pulmonary O2 toxicity.


I would recommend taking a Nitrox course. The basic Nitrox course will not got deep (pun intended) into a lot of the physiology, but will give you some basic knowledge about O2 toxicity and alternate breathing gases.

[Popeye]

"It looks like the habitat divers were using some sort of re-breather"
That was the Mark 6 Semi-Closed UBA which was set up to use the HeO2 bottom mix, some of the 3rd team on SeaLab 2 did a few excursions to 300 feet from the habitat. I was on The Mark 6 test team here in Panama City in 1963 and returned in 1964 to work on the Sealab 1 program here and in Bermuda. returning again in 1965 to provide Photo support and train SeaLab divers in use with the Mark 6.
A few Mark 6's were still around in the early 1980's when it was replaced with the Mark 15 closed circut UBA.

[SurfLung]

- Luis, I will definitely look into the Nitrox course... It wasn't around when I started diving in '69 and it didn't pique my interest when I first heard of it a couple of years ago... It now sounds fascinating. Thanks for the tip.
- Wow Popeye... Thanks for sharing your experience with Sea Lab and the advanced diving equipment of the day.