Do you think the guys on the titanic submarine will be rescued?
For those who are unaware: A couple billionaires, a pilot, and one of the billionaires' son are currently stuck inside an extremely tiny sub a couple thousand meters under the sea (inside of the sub with the guys above).
They were supposed to dive down to the titanic, but lost connection about halfway down. They've been missing for the past 48 hours, and have 2 days until the oxygen in the sub runs out. Do you think they'll make it?
the second one is quick and easy. the first one would be tough. imagine dying breath by breath. most people aren't afraid of death, it's the dying part...
That depends on if their CO2 scrubbing lasts longer than their O2 supply. Your body can't actually feel a lack of O2, the feeling most people associate with suffocation is actually your body detecting a build up of CO2 in your blood. If they can keep scrubbing the CO2 out of the air after they run out of O2 then they'll just start to get lightheaded, kind of drunk feeling, tired, and eventually just pass out and die. You actually barely feel it happening which is why O2 sensors are so important when working in poorly ventilated confined spaces. I know this first hand because I work with bulk liquid nitrogen and I've damn near knocked myself out a couple times via an inert gas cloud. One moment you're perfectly fine, then you just start to black out and it dulls your senses so much that you don't even have the brain power to process what's happening. Them running out of oxygen more slowly will extend that process a bit but it still isn't a painful process and the thought numbing effect from your brain running out of oxygen keeps it from even feeling particularly alarming.
So as long as they can keep scrubbing CO2 then at least they won't die a particularly "unpleasant" death. That is assuming the sub didn't just pop from pressure like you said.