This is a one-page set of rules for American Civil war naval and river battles.
naval
WWI and WWII Naval Rules
Steve Burt offers a set of free wargames rules for WWI and WWII Naval combat.
Letters of Marque and Reprisal Age of Sail Wargames Rules
Letters of Marque and Reprisal is a set of free wargames rules for replaying battles in the age of fighting sail. It’s meant for battles where each player would control one ship, rather than a squadron or fleet. It looks perfect for pirate battles.
Sails of Glory Solo Rules
Here are a set of interesting rules for solo play of the Sails of Glory game.
Victory At Sea – General Chase! Age of Sail Rules
David Manley offers Victory At Sea – General Chase! a set of free wargames rules for the Age of Sail.