The rules of this game were sent to me by Eugene Laukamp. This game is said to be invented in Germany around the first world war, and to have been popular in Germany for some time. The circular hierarchical structure and the limited types of movement is typical for games from this game-family.
The game is played on a board, composed of twenty hexes. There are three types of pieces: cruisers, destroyers, and U-boats. Cruisers and destroyers form together the two types of battleships. While cruisers and destroyers move on the corners of the hexes, the U-boats move on the middles of the hexes!
Each player has three U-boats, two cruisers, and four destroyers. The opening setup is displayed below. Note that the bottom hex is a harbor for U-boats; the top two corners of this hex form the harbor for the `battleships' (cruisers and destroyers).
Each cruiser moves along the sides of hexes, and may move one or two hex-sides in a turn. A cruiser can take a destroyer, when they move to a hex-corner that is one hex-side away from an enemy destroyer. Cruisers cannot take U-boats. Instead, when a cruiser moves to a hex- corner, belonging to a hex that contains a U-boat, the cruiser is taken. (In this way, a cruiser can commit suicide. A cruiser can take a destroyer and be commit suicide to be taken by a U-boat in the same turn.)
A U-boat moves from the inside of a hex to the inside of an adjacent hex. When a U-boat moves to a hex, which has an enemy cruiser on one of its corners, the enemy cruiser is taken. When a U-boat moves to a hex, which has an enemy destroyer on one of its corners, the U-boat is taken. Thus, U-boats cannot take destroyers. It is possible to commit suicide and simultaneously take a cruiser by entering a hex with an enemy cruiser and an enemy destroyer on its corners.
A destroyer moves along the sides of hexes, and may move one or two hex-sides in a turn (i.e., similar as a cruiser). A destroyer can take an enemy U-boat, by moving to a corner of the hex containing the U-boat. Destroyers cannot take cruisers. (You can now guess this:) When a destroyer enters a hex-corner that is one hex-side away from a cruiser, the destroyer is taken. Similar as above, it is possible to commit suicide and take a U-boat in the same turn, by moving to a corner of a hex, containing an enemy U-boat, and this corner one hex-side away from an enemy cruiser.
Players move turn-wise one of their pieces, as described above.
The first player that moves a battleship (cruiser or destroyer) to the battleship-harbour of the enemy, or that moves a U-boat to the U-boat harbor of the enemy, wins the game.