I did not see this until just now, and alas, I actually don't know how.
Ship maps are a bit vexing for me. There's an encounter on a 30 square long ship in adventure 3, and realistically the ship ought to be able to move, but unless you've got the biggest table in the world, shifting a cardboard cut out of a ship across a gridded battle map gives you pretty limited movement options.
I hope the game turned out well.