Swim Attire on a Cruise
It would depend on the cruise line and destinations. There were several gentlemen wearing bikinis around the pool on my Holland American cruise during the last two weeks . I even wore a HIS bikini pulled into a thong on the Deck 14 forward sundeck. A brave woman could probably even go topless up there. I also wore one in St. Martin where I saw several women in thongs/ g's and a couple women were topless (None from the ship) There were also a couple of guys were in speedos. There were also men in bikinis at several other ports. Trunk Bay St. John I wore the bikini to snorkel and saw several girls in thongs. The most surprising was at Half Moon Cay where there was a couple where the guy went running on the beach in a brief brief and the wife actually went topless for a bit. My wife & I set up away from the crowds and this other couple set up fairly close.
I doubt Disney would be tolerant, but even though it is made fun of because of it's reputation for catering to the nearly dead, Holland does have a lot of Europeans and Canadians who don't blink at skimpy attire.
We do lots of cruises. The trend seems to be returning to shorter, tighter swim suits on guys. I've been seeing lots of the old tennis short lengths (I think they were 7 inches) and square cut lycra trunks.
I'm there to enjoy myself and not worry about what others think. I wear a speedo type tan thru suit with 1 inch sides. I have noticed that at the beginning of the cruise, you'll only find a couple of guys in speedos but by the end of the cruise, you will see a lot more. Some men need permission to wear theirs. When they see you're wearing one, they will join in. Enjoy your cruise!
My Wife n I have been on a few Disney cruises. We like to go to the adult pool and decks which as you may imagine are more sparsley populated than the kids pool. I wear string bikinis and square cuts there and have had no problem. At the ports i wear strings. Again no problem.
I will go on my first cruise next week and will wear my speedo brief, but also have a boxer style. I conferred with my roommate who has been on several cruises and he will bring the same. I may bring a thong just in case... I don't think my ship has gender segregated sauna. But we'll see.