Grand Fleets demo rules

Majestic 12 games has these demo rules for their Grand Fleets miniature wargame. My group has played these and really enjoys them. Majestic 12 explains:

Grand Fleets is a comprehensive miniatures game of dreadnought-era naval warfare. In addition to rules for everything from ships to aeroplanes, Zeppelins to submarines, the rulebook includes:
Data cards for over 120 ships, plus guidelines for converting any ship of the period to game values; Eight scenarios encompassing conflicts from the Sino-Japanese War of 1894 through the opening salvoes of World War Two, including several variants; Fifteen pages of weapon data, covering all major gun and torpedo models in use through 1939, over 200 aeroplanes, and more than 20 airships; and Optional rules for flotillas, night-fighting, smokescreens, and more!

Iron and Steam Rules

Iron and Steam is a set of free wargames rules for pre-dreadnought Victorian naval actions.

Iron & Steam is based on a set of Victorian pre-dreadnought rules written by a friend in the late 1980s. They’ve evolved over the years though I’ve not played them recently. The game is meant to use sheets for each ship to record movement orders and accumulated damage. I had a fairly complex set up of mail-merged MS Word documents to generate the record sheets. But, of couse, they no longer function so I’ll have to come up with another system of generating them. That may take a while. Still… the game is playable if you’re willing to keep track of the statistics on a piece of paper. I know, I know… so high tech…. The methods of calculating the factors and a number of pre-calculated ships are included in the rules.

Coal and the Kaiser naval miniatures rules

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.