Kaisen Game: Navy Blue is a Battleship variant. On a 8x8 grid, both players place four ships of varying size. Each round one player guesses a grid of the opponent's board and is told if it was a hit. The winning condition is to sink all enemy ships first. The speciality of this variant are a few extra weapons with a limited usage which can bomb multiple fields at once. There is also a radar which reveals four fields of the enemy board.