If you are any fan of historical themed games then you have likely seen or played some of the total war series (Shogun Total War, Medieval Total War, Rome Total War, etc.). The next game in the series, coming out next year, is set in the Napoleonic era and includes, along with the normal campaign and land battles, sea battles. Thought that might catch the interest of some pirate fans.
Recent article: http://pc.gamespy.com/pc/empire-total-war/924111p1.html
Gameplay videos: http://www.gametrailers.com/game/6795.html
I've been a fan of the Total War games for a while now and am really looking forward to this.