It’s way, way worse than a spaceship. On a spaceship you’ve generally got enough water and oxygen via the fuel cells to last a week or two, you’ll probably die of overheating or CO2 (CO2 is also the issue with a large sub disaster like the Kursk). On a sub like this…you’ll freeze or die of lack of O2.
Also, loss of pressure on a spaceship is bad but survivable. 1 atm to zero. The Byford Dolphin was 450 meters down and that was 9 atm to zero. The Titanic is 3800 meters down (0 to 380 atm, the other way round, explosive compression.).
If Apollo 13 had happened on a sub it’s arguable there’d not be enough left of the craft to show up on sonar.
Wait what difference are you trying to describe between lack of O2 and overabundance of CO2? Both of these go hand in hand in these situations right? There isn’t a CO2 scrubber on a submarine that doesn’t work either. That seems like a terrible way to go because CO2 hurts when it’s built up in your blood
There are chemical CO2 scrubbers that don’t need electricity, so in principle you can die from lack of O2 while having livable CO2 levels. (though now you mention it I feel that the sub that failed it’s depth rating test due to hull fatigue and then posted an FAQ about how it didn’t need a rating because “disruption” does not have emergency CO2 scrubbers)
