I've been tempted to see how my cat does on my boat... but the thought of kitty litter on the boat... and kitty litter getting overturned... has kept her on shore.
Lots of animals love boats and the water. I think the original poster was looking for tips on training their animals for boating, not your opinion on animals aboard.
Let me know how the cat thing goes... but I think I'd be in big trouble throwing Kahlua overboard and telling her to climb the rope. She's a Himalayan ragdoll runt... she'd probably be hiding in a locker for the first few trips.
My girlfriend has a sugar glider... I'd love to train it to jump off the rigging and glide down to my shoulder! Any tips for that?