Drowning in a spacesuit? Not how I'd imagine going out. How would a snorkel help given that there is no true waterline in weightlessness?
I remember reading the Space Shuttle specification and there were contingencies for abort at various stages and if an incident happened what to do about it.
I don't doubt that they have contingencies for deaths on board, though. I'm sure everything has a plan. Sort of the space equivalent of the US military having plans to invade Canada and Mexico, except more likely to be needed.