Andy Watkins offers Nelson’s Wars, a set of rules for miniatures battles in the age of fighting sail. The mechanics are based on the Silent Death rules, which use dice of different sizes (d4, d6, d8, d10 etc.) to distinguish between different weapons systems.
Admiralty is a set of free miniatures rules for the age of fighting sail. Its designed for 1/2400 miniatures. The authors write:
Admiralty is a set of miniature wargame rules that re-create battles from the age of the fighting sail. The game concentrates of the core features of period naval combat including sailing, cannon fire and boarding actions. The rules are geared to allow large battles to be fought over realistically scaled areas of “sea” as player struggle to pummel, dismast and capture their opponent’s vessels. The rules are split into six sections, each of which deal with a particular aspect of the game. Playing aids such as ship log, firing arc and the all-important combat chart can be gotten on the main Admiralty home page.
Here are some instructions for making a beautiful game board — complete with islands for WizKids’ Pirates of the Spanish Main constructable miniatures game.
Coal and The Kaiser is a set of free naval miniatures rules.
Author Leonard Heinz writes:
This is a game of low to moderate complexity portraying tactical naval combat in the period from 1904 through 1918. While it will not yet you play Jutland in a day, it will let you play some fairly large actions reasonably quickly. It uses a scale of 4 minutes to the game turn and 1000 yards to an inch on the playing surface. The rules focus on big ships and big guns: battleships (and particularly the Dreadnought-type battleships that began service in 1905), battlecruisers and armored cruisers.
Veteran Gamer Lou Coatney offers a page with printable WWII ship plans from US government sources. I’ve got an idea about printing the side views,coloring and basing them and using them for a naval game.