Why are cruise ships always named after women?

Who's her you ask, the cats mother?
But it's a good point I think; why are cruise ships always named after women, or refereed to as a her? Off the top of my head, and I'm prepared to stand corrected here, I could only think of one cruise ship currently in service named after a man and that's the Paul Gauguin, named after the French impressionist of the same name. So why is this; how did this situation arise?
Well as always there's no easy answer to the question, however there are a couple of pretty good theories to explain it........