A few time wasters you can play on your browser
Here's a couple battle at sea flash games:
http://gameinabottle.com/
Master & Commander
http://www.pog.com/games/Engage_And_Destroy
Black Sails
http://www.pog.com/games/Black_Sails
Good work games...err not that I play games at work... :P
If you have more time to invest check out Pirates of the Burning Sea
http://www.burningsea.com/page/home
Theres also Sword of the new world:
http://swordofthenewworld.gamersfirst.com/ (http://swordofthenewworld.gamersfirst.com/)
Its sort of free (like 2nd life). I played it for a short time.
Disney's pirates online is also free. Well it's free for a few days then you can continue to play but in a limited fashion. I have had some fun playing it!
Fight like a pirate...
www.fightlikeapirate.com