How to escape from the ship nostalgia?

Basically, after you've accessed the laptop to find the location of the silver dragon knife, in the ensuing fallout of the explosion that your "accessing" triggers, the Nostalgia is now upsidedown and sinking fast.
Retrace your steps to find your way back to a small window which you'll need to crack with your elbow then kick the glass to smash it before swimming out to trigger the cut scene. Along the way, remember to make use of oxygen tanks [with breathing masks] floating along where you need to go. Also, there is an underwater pirate you must fight as well, so just follow the screen prompts and press the buttons asked for as as quickly as you can. Good luck:}