There weren't many women on the ocean back in the sailing days, on long voyages men would rape eachother and form groups for protection and gang rapes.
When another ship was take over by pirates all the captive sailors would be raped until they were used up and thrown overboard, then the pirates would turn on eachother again.
Sometimes homosexual rapes would happen on a ship before it even left port, sailors jumping overboard and swimming towards the shore only to be chased back by crowds of people masturbating to the sight of naval buggery.