There are a lot of ways to die in a sub, not many are pleasant. But sometimes they did come to rest, mortally damaged, on the bottom. I'd rather take a chance with a Stenke Hood from 700 feet than die for sure in the sub.
Went to 2nd Class Diving School - SRF - Subic in '66. Our qualification dive in SCUBA was 120' on a sunken LST. Visibility was unbelievable. It's really awesome to dive on a wreck and makes one wonder about the history of the ship.
The LST was sunk during WWII. The bow doors were open and the ramp down.
When we went to make our qual dive in Mark V, someone made an error on location and rather than diving to 120', the bottom came up and greeted us at 30'. Sunk up to my waist in mud and silt.
Been many, many years since I've put on my gear - should probably donate it to a museum. :)
You an me both FRiend. Beats just sitting there waiting for your time to expire, dying from exposure and lack of oxygen.