I might join them someday, but I think I'd want a battle ship with fully-operational guns

Here's an idea... Outfit the sailboat with Lego trebuchets (just like an old Roman onager - fireballs are optional ), and put Grouchy on-board as the captain/bombardier. You'll go and hide in some bushes in the marsh nearby, and your remote control handy, while Grouchy will spot targets, and reload the trebuchet. Now, start shooting people on the shoreline with Legos (the deadliest projectile known to mankind ), then cry havoc, and let slip the bricks of war.