[twh270]

It's not really about the distance; it's about how drastically conditions change in 100m depth of water -- to the point that very specialized equipment is necessary for humans to survive, and if we're not careful on the way up it's gonna be a Very Bad Time possibly (or even likely) resulting in death.

[wpietri]

For sure. This got me thinking about how humans need special equipment to survive long even 1m below the surface, and the problems just get worse with depth. Wikipedia has nice coverage of the way we've iterated deeper and deeper: https://en.wikipedia.org/wiki/History_of_underwater_diving