pilots of both nations end up in the water, and both can be rescued by your sub.
lifeboats arent empty. when first lowered they will have ppl aboard, empty ones are due to being tipped by a ship wake ( i cant confirm that) or being rescued by being in the vicinity of a allied ship. ( they dissapear you dont see them climb aboard, but that is exactly what happens when you rescue a pilot, they dissapear)
ive seen pics in this forum of dead ppl on deck, you also see sailors and officers strolling about the decks at all times, ive seen one hide (crouch and cover head) next to a bulkhead whilst under attack from allied planes.
there is a fair bit of detail now
i think the number of lifeboats you see are down to ingame settings for graphics, but cant confirm that either
as ive only got one pc hehe.
edit:
ah well you wait for one post and then two come along at once