AND additionally deep diving will be risky for some time to come - for similar reasons. Mostly because when something fails 35,000 ft below sea surface, it will be very hard to “fix” it - nor bring it up quickly to apply repairs.
Robert Ballard, the deep-sea explorer who discovered the wrecks of the Titanic, Bismarck, and Yorktown observed that between the 1960 descent of the Trieste to the Challenger Deep in the Mariana Trench and prior to the Titan loss and 2023, there had been precisely zero deep sea submersibles and zero lives lost exploring the deep sea. He attributed this to the conservative engineering, extensive testing, incremental expansion of the operational envelope, and professional operation of exploration vessels, as opposed to the Home Depot bricolage of OceanGate’s “vessel”, which had never been tested to a depth greater than its supposed operational depth (and hence, had no safety margin), nor monitored for deterioration of its structure by repeated pressure cycles.
Compared to the deep ocean, rocket flight and space operation is a pretty benign environment. While things can go wrong very quickly and spectacularly, a crew escape system that gets people out of harm’s way quickly is a straightforward engineering job and has worked on all of those few occasions when it was needed. In space, you’re only dealing with a one atmosphere pressure differential, so even if you get a hole in your spacecraft, things happen relatively slowly and you can fix it (if it’s accessible) with nothing fancier than duct tape.
When you’re surrounded by water at 300 atmospheres, if something goes wrong, it’s all over in less than human reaction time.
Yeah! Pressure increases 1 atmosphere for every 18’ of water, IIRC. THAT would put the pressure of the Titan, sitting at some 35,000’ under water, at some 1,900+ atmospheres. It’s why diving even to 100’ can be dangerous.
Deep dives may have been safe so far, but I would propose that is primarily because there have been very few people who have done that, and fortunately they’ve been really respectful of the depth. BUT there have been numerous episodes of death or at least the Bends at much shallower depths, often just because they have been viewed as “recreational” dives and not taken as seriously as they should have been. Even in the not-so-long-ago diving for the U-boat found off the coast of NJ, one died and the other suffered serious after effects from coming to the surface too quickly, while yet another experienced diver just drifted off; hi body was found about a month later. (All this was documented in a book called The Shadow Divers.)