Sorry, yes, this is what I meant. There is less "difference" of pressure in vacuum vs. depths of the sea.
a) You don't strap yourself into a seat on top of a few hundred tons of high explosives prior to getting started. Major plus in my book.
b) Barring catastrophic failure of the pressure vessel, all you need to do to get to a safe-ish state is to jettison enough weight to become positively buoyant - and off to the surface you go.
(When diving in shallower waters, in a suit, this would be a concern; however, as you are at (or very close to) surface pressure throughout the dive - no problem.)