Pirates

Pirate Bay
Can support up to 5 ships (Corvette or Frigate)
Pirate Haven
Can support up to 10 ships (Corvette, Frigate, or Galleon)
Pirate Fortress
Can support up to 20 ships (Any)
Pirate Ships:
Corvette
Frigate
Galleon
Battleship
Aircraft Carrier
Supports 1-3 Airships