Hit the ESCAPE key. Click of the "AJ" button on the menu at the top of the screen. You can then place your opponet under manual control(even in campaigns.) Make all the enemy ships surrender. If you want, change your opponent back to computer control. Even if you leave them on manual, you still get all victory points and prizes.
Attack Tip
Open full sails and come up behind your enemy untill you are about to crash. Then turn to the side and rake them with a broadside.(this is not advised for a frigate that has the nerve to attack a ship-of-the-line. You may not clear the enemy's guns and end up worse than them.)
