The year is 2065, and the world is united in peace. Mankind has conquered the stars, so attention turns to the exploration of the oceans. The vast, uncharted depths provide valuable minerals, but also hide new and mysterious alien races, not all of whom are entirely friendly.

The Aquaphibians take offence to the surface dweller's forays into their undersea kingdom. Titan, their ruler, swears to invade the surface world in revenge. All that can stop him is the World Aquanaut Security Patrol - WASP.

WASP is an organisation of fearless individuals dedicated to preserving world peace. Their key weapon in the fight against the Aquaphibians is Stingray, a futuristic, nuclear-powered submarine. Troy Tempest is its heroic captain, ably supported by his team at Marineville headquaters:

George Lee Sheridan: nicknamed 'Phones' due to his expertise with the underwater Hydrophone communication system.

Marina: A mute, tail-less mermaid. She was enslaved by Titan, who has threatened to destroy her people if she ever speaks.

Atlanta Shore: Marineville's assistant communications officer. She supervises the launch of Stingray. She loves Troy from afar, so has a friendly rivalry with Marina.

Commander Sam Shore: The head of WASP, he was once involved in a submarine acccident. He uses a special hoverchair to get around Marineville due to his injuries. He is Atlanta's father.