Was intentionally left out. These are troop transporters, not leisure cruises. There really isn't all that much you can do, and the game assumes you are already spending the day trying to keep troop morale at least level.
You can be religious though, perhaps a priest on board, or a religious idol could give the men a somewhat safe feeling during there trip.
You could also be an atheist and the men would fear the gods (or 'er big blue deep's) wrath and shiver by every wave that strikes the boat.