I must add a little warning here against using the medic

.
If one of your crewmen is injured during a patrol, when you reach back port you are awarded a specific medal (can't remember its name right now) specifically for wounded personnel (some sort of Purple Heart).
But, if the crewman has fully recovered via the medic, you find yourself in the position of being unable to award that medal. So if you want to use that medal, you must keep the man wounded until back at base, i.e. to put him in another compartment than the medic.
There was also talk here that the medic makes crew recover faster from fatigue, but this hasn't been proved 100% IIRC.