Highest ever altitude dive

[Rhone Man]

I was reading an article about Ojos del Salado lake, and I was wondering, does anyone know what the highest altitude a dive has ever been recorded at (and where)?

 

[Walter]

I don't know the record, but Jacques Cousteau's team dived Lake Titicaca (12,500 ft) in the early '70s.

The NOAA Diving Manual warns:

WARNING​

DIVING AT ALTITUDES ABOVE 10,000 FEET IMPOSES SERIOUS STRESS ON THE BODY AND IS STRONGLY DISCOURAGED.

 

[Walter]

I just found this:

Tilicho lake is one of the highest lakes in the world.[1] It is 4,949 m high in the Annapurna range of the Himalayas in Nepal.[2] Another source lists Lake Tilicho as being 4,919 meters high (16,138 feet).....It is believed to be the site of the highest ever altitude scuba dive, although no official world records are recognised. A Russian diving team consisting of Andrei Andryushin, Denis Bakin and Maxim Gresko conducted a scuba dive in the lake in 2000.

and

A rival claimant for the highest ever altitude dive was Frenchman, Henry Garcia, who claimed to have conducted a dive at 5,900 meters Lago Licancabur in 1995. If verified, this dive would be over 1,000 meters higher than the dive at Tilicho Lake.

and

A team of divers made a series of dives researching and exploring a shipwreck in Lake Tahoe in 2002. The divers reached depths of 400 feet at an altitude of 6,230 feet using specialized equipment and decompression software as well as 6 different breathing gases. This would be a likely claimant for the highest planned decompression dive in the world.

I have no idea how accurate any of that might be.

 

[Dirty-Dog]

In Colorado:

George Town Lake, George Town Colorado
elevation 11,950'

Turquoise Lake, Leadville Colorado
elevation 10,000'

Twin Lakes Reservoir, Colorado
elevation 9,200'

How high on the insanity scale do these places rank?

 

[Thalassamania]

I helped Charlie Brush prepare for his exploration of high altitude lakes in the Andean Mountains in South America, including an expeditions to the world's highest lake in the crater of Volcano Lincancabur, where he established a world altitude record (19,300 feet) for scuba diving.

 

[Doc Harry]

Wow, 19,300 feet.

 

[boulderjohn]

I just found this:

A team of divers made a series of dives researching and exploring a shipwreck in Lake Tahoe in 2002. The divers reached depths of 400 feet at an altitude of 6,230 feet using specialized equipment and decompression software as well as 6 different breathing gases. This would be a likely claimant for the highest planned decompression dive in the world.

I have no idea how accurate any of that might be.

In Colorado:

George Town Lake, George Town Colorado
elevation 11,950'

Turquoise Lake, Leadville Colorado
elevation 10,000'

Twin Lakes Reservoir, Colorado
elevation 9,200'

Lake Tahoe has had a number of decompression dives done on it. UTD divers have done it, and, believe it or not, they made no adjustments for altitude. They don't believe it is necessary.

My only diving in the higher mountain lakes in Colorado was in Jefferson Lake (10,600 feet). We did not do any decompression on that day. We were planning to get some snowmobiles and go there for some ice diving this winter, but that fell through.

We may try to do some decompression diving there this summer. If so, that will raise some discussions about the decompression schedule on our team, since, as I said, our agency officially does not believe altitude needs to be considered.

I, on the other hand, ...

 

[Thalassamania]

After a whole lot of looking into it, and talking to people, the decision was made to make the dives using pure oxygen rebreathers (Carlton Cobra). The Andean lakes were pretty shallow anyway.

 

[aquaregia]

Lake Tahoe has had a number of decompression dives done on it. UTD divers have done it, and, believe it or not, they made no adjustments for altitude. They don't believe it is necessary.

I have no training in deco diving, so I was hoping for a bit more clarification on this. I'm assuming the thinking is that Tahoe's around 0.75atm, so it's only the equivalent of 10ft deeper? I'd rather consider that "double surface" would occur at 16ft, "triple surface" at 41ft, "quadruple surface" at 66ft, etc. Or is the idea that you run straight down the mountain so you offgas at sea level?

Again, no experience or training in this at all, so I'm sure some of my thoughts are way off.

 

[Blackwood]

We may try to do some decompression diving there this summer. If so, that will raise some discussions about the decompression schedule on our team, since, as I said, our agency officially does not believe altitude needs to be considered.

I, on the other hand, ...

I don't know if it's sufficient to say they don't believe it needs to be considered. Rather, that's in incomplete statement. It needs to be qualified: "while respecting this particular ascent methodology."

If they taught a "get shallow and out of the water as quickly as possible," the added surfacing gradient relative to sea level tables certainly would be a factor.

(note I'm not saying it doesn't need to be taken into account, just expanding on your posts)