It seems as if the crew requirement is the minimum number of crew required to operate a vessel. As such, if you go raiding in your galley and lose some crewmembers, can you get back? What sport of penalties could you take for operating at less than capacity?

For larger ships I think that a reduction in the number of continuous hours a ship is operated would be reasonable. For example, with a warship at 40 crew you could only sail for 16 hours a day instead of 24 hours.

However, galleys are rowed, so would you just tie the speed to the percentage of the crew that you have? For example, at 40 crew you could only move at 2 mph.

There seems like there would have to be a lower limit somewhere however, as one or two people would never be able to move a galley on their own no matter what.