Great thread. Laughing so much that my face hurts!
Thankfully our cat has turned into a stay-at-home most of the time. He's a scaredycat anyway, doesn't like strange noises, but will run up to greet the car when we get home. Has run away from more animals than he's ever caught, and has taken to guarding the next door neighbour's rabbit since our guinea pigs passed away.
All in all, I think he'll take rather well to living on a boat. There are nooks for him too explore, people for him to meow at, various vantage points for him to safely survey the passing world, and very few cats to contest his ownership of the boat. 'cause he's a complete wuss!!