The title of this game translates from Japanese as 'Great Underwater War'.
This is a superb game, created by the same team behind the legendary R*Type series. The superbly-rendered graphics are very similar in style to Irem's R*Type Leo, released a year earlier. Kaitei Daisensou would prove to be Irem's last 'traditional' arcade shoot'em up, although two further R*Type sequels were released for home consoles (see R*Type Series section for more info).
This game is known in outside Japan as "In The Hunt
NAG, the game designer didn't like shoot'em ups with forced scrolling. The idea of the submarine came one day when it feel asleep in a park and was woke up by the sound of a near fountain.