Though the Harpoon Series of boardgames shares the title and is listed in the Adapted from Board Game, Boardgame is not a theme for this game. Both the boardgame and the videogame try to mimic naval warfare as realistic as possible within their own medium. As such, both are basically Adapted from Reality.
Do not expect to play the boardgame. This game is a (real time) simulation, not a boardgame.