Crash Dive (Atari 2600)

Treasure hunting is in your blood... and you're willing to risk it all for a crack at the famed riches of Ramara. As captain of the flying sub, Sea Hunter, you and your crew face danger from air, land and sea. You see, the "X" that marks the spot lies just off the coast of a hostile enemy country. But penetrating their waterways is the least of your troubles. As you clear the skies and enter the murky waters of the deep, you'll find unimaginable adventure. Sharks and sting rays, mines and monsters, the promise of gold, all create an underwater adventure you won't soon forget. It's a truly submerging experience.