Forgive me....I wouldnt have considered it before, but as we are also taking a cruise, and over on those boards its just as absurd to bring your towels, just use the cruise lines - even in port! Its too hard to get your own dry. You do get charged if they are not returned though!
Might look into the rental or buying some cheapies- I really dont want to pack them - 5 of them takes up a lot of room!