A set of modern tactical naval wargame rules. Written by Larry Bond and Chris Carlson. There are at least 4 editions.
It is a detailed naval wargame available short of the classified ones. Harpoon was used by Tom Clancy during preparation of his first novel, The Hunt for Red October, and also for modelling the story for Red Storm Rising.
The game itself is, as most serious naval wargames, meant for play with miniature ships. All ranges are measured in nautical miles. Harpoon uses a free gameboard. There are no hexes or premeasured abstractions. Ships, subs and planes move in degrees and centimeters or inches. Alternatively, the game can be played on graph paper and positions plotted in accordance with orders given. In most games, a referee is useful for those cat-and-mouse scenarios where the referee coordinates the plottings of the players, revealing the enemies' plottings when in range.