I'd never chosen Hawaii in FS9 until last weekend. I put a Curtiss Jenny at Honolulu Intl and took off. And I noticed that FS9 actually has cruise ships going around the harbor!
And so I became a real jerk and buzzed their decks a few times in my plane. I imagine that would get me in some real trouble in the real world.
Although they were probably shady characters, since the cruise ships didn't have any markings or anything.
There weren't any people on deck either. My wife said "Of course there aren't! Everyone fled from the nutcase in the red biplane that's about to crash into them!"
There are cruise ships near the harbor, and if you fly along the coast you will see sail boats near the shore in different spots. Also if you fly into the harbor you can find the USS Arizona memorial.