J.✰.
I like the "Got Cruise?" except I think of Tom Cruise.
In addition to Marda's suggestion, change it to "... sea the world!" instead of "see" b/c they'll be in the ocean. Or even do "....to sea Xlocation."
How about a simple "All aboard!" with a stick drawing of a boat with water
Ha - FangedBunny's made me laugh. I like shirts that make me laugh.