The wreck of the Edmund Fitzgerald is located at a depth of 530 feet (162 meters) below the surface of Lake Superior. That's an extremely risky technical deep dive. There were probably more people in space than non-saturation diving at this depth.
Presumably also open circuit not rebreather given this was mid 90s. It's a pity the article doesn't detail their dive plan, the gas quantities must have been staggering.
Nowadays this type of diving would be done using an eCCR (and backup open circuit), where some software on a microcontroller controls the amount of oxygen in a breathing loop. A scrubber (hopefully) removes the CO2. Changing the gas mixture as you go is required to reach these sorts of depths because oxygen becomes toxic at pressure, and gas density itself can cause issues with breathing.
Right, Terrence Tysall and Mike Zlatopolsky (Zee) dove the Edmund Fitzgerald in 1995 using open circuit gear. This article by Tysall gives some details of their dive plan.
500-foot waters but the ship was 700+ long. The size of cargo ships boggles the mind. The largest space rockets are toys compared to any modern cargo ship.
Good lord, ascent must've taken hours at that depth. I felt daring going down 40 meters in Belize, 164 in pitch black ice cold water, trimix and hours of deco gass on the way up? No thanks.
