Plunder, developed by Certain Affinity (Whose lead designer is Max Hoberman of Halo 2 and 3 multiplayer fame), is a real time multiplayer strategy game inspired by titles like Settlers of Cattan. On a hex tile board, players take control of their own pirate ship and attempt to gain domiance over the ports that are placed around different spots on the map.
Capturing various areas will yield spoils that will allow you to upgrade your ships with faster speed, stronger shields and better firepower. Pointing and clicking on a hex area will start moving your ship to that space and passing by an enemy will initiate automated cannon fire between the two ships. The game is won when one player or team gains control over the majority of ports.