Ship and vessel battle maps
A ship is the most constrained battlefield in the game and that is exactly why it plays well. These are drawn as deck plans with the deck cut away where it needs to be, so the hold, the cabins and the space below are visible rather than implied by a hatch.
Running one at the table
Ships are about bulkheads. A hold drawn as one open space is a barn that happens to float, so these are divided into real compartments with real doors, and the ladders between decks become the chokepoints the whole fight organises around.
How big to make it
Most vessels are long and thin, roughly 30 to 45 squares bow to stern and 10 to 15 across the beam. A boarding action wants both ships, so allow for double the width.
What you can make
Pick one and RPGenie writes the map from it. This is not a library of 15 finished pictures: they are starting points, and the map you get is generated for your table.
Ship and vessel battle maps shared by RPGenie users
Make a ship map
Every art style
The same map, drawn twelve ways. Style is picked per map, so a campaign can stay in one look or change with the scene.