Bowser's Battle Yacht is a yacht that belongs to Bowser in Mario Party 6. He rides it around Castaway Bay. If a character lands on it, Bowser will give the character a Shadow Star or steal other valuables, like coins.
Landing on a ? Space will make the Bowser's Battle Yacht move so whoever lands on the Star Space next time gets to see DK's Boat and not the yacht. Also, when taking the raft ride in the northern part of the board while Bowser's Yacht is facing it, the player must be careful; Bowser will fire three cannonballs at the player, and if one hits them, they lose five coins and stop moving.