If you play a lot of Pirates, you may already know this, but it took me awhile to figure it out. When your ship is dead, you're not out of the game!
If you have any cannonballs left in your dead ship, wait until an enemy ship is near you... the closer the better... then double click on your ship. Your ship will blow up sending flaming cannonballs in all directions. I managed to actually kill an enemy today even though I was already dead!