While the Stingray crew go to the rescue of two crazy treasure hunters, Troy falls down a crevasse, runs out of air and goes into unconsciousness. When he comes to, he discovers he doesn't need breathing equipment to breathe and he is now the richest man in the world.

After receiveing the 'Aquanaut of the Year' award, Troy is surprised to find himself the subject of 'This Is Your Life'. His most exciting adventures are re-capped in flashback before the interviewer pops the important question - are he and Atlanta more than just good friends? Before he can answer an alert is sounded, leaving Atlanta to assure the interviewer that there isn't enough time for romance in the WASPs!

While waiting for Atlanta and Marina, Commander Sam Shore shows to Admiral Denver films showing the previous missions that Troy Tempest and Phones had with the submarine Stingray.

When their vacation is cancelled, the Stingray crew probes into the ocean depths, They discover a deep shaft that leads to desert-like plateaus. Before they can complete their investigation, a wall of water turns the desert into an underground sea. Swimming desperately back to Stingray they attempt to relocate the shaft before their oxygen runs out. Out of desperation they enter the first shaft they see. They surface near a beautiful tropical island. The perfect place for a holiday

Shore takes up Admiral Denver's challenge that the WASP's of today can't take the rigours of an old-time sailing vessel. Phones and Lt. Fisher are assigned to Denver's crew. When a storm hits, Denver is knocked out and loses his memory and Phones and Fisher are cast adrift in a small dinghy. They are rescued by Troy who has been following in Stingray but, when Stingray approaches the sail boat, Denver begins firing his guns wildly at the sub. Troy, however, succeeds in overpowering Denver who later regains his memory in hospital.

While trying to decide what to wear to Atlanta's fancy dress ball, Troy falls asleep and dreams that he and Phones are pitted against a race of underwater cavemen who plunder the cargo of a vessel varrying radioactive material. Troy awakens from his adventure, inspired to wear a caveman outfit to the ball - as, in fact, does everyone else!

Phones is convinced that he is unfit for duty when X20's plan to discredit him nearly succeeds. Disguised as a psychiatrist. X20 further discredits Phones' claim that he really did hear the sounding that drew Stingray away from their escort patrol. It's Lt. Fisher who discovers X20's remote sounding device that clears Phones.

The de-throned Ali Khali, brother of evil dictator El Hudat (who is in Marineville Jail) visits Marineville. Meanwhile, Surface Agent X20 helps El Hudat to escape from his imprisonment by swapping Ali Khali, who has an exact likeness, in his place. Commander Shore discovers the switch so the Stingray crew and Ali Khali give chase.

While the Stingray crew are on shore leave in Casablanca, a merchant sells Phones a map leading to ancient treasure. However, when Troy refuses to search for it, Marina secretly alters Stingray's course.

An underwater alien takes an ex-WASP admiral and his wife captive.

Commander Shore's friend Admiral Denver claims to have seen the Loch Ness Monster. As a result, the Stingray crew travel to Scotland to see if the legendary beast exists.

Thinking all the commotion at Marineville signals the visit of a VIP, X20 kidnaps the man and delivers him to Titan. The undersea ruler is surprised to learn that X20 has brought Duke Dexter, a pop singer. Titan is convinced that Dexter is an ally of the underwater people by the way he drives the Terraneans crazy with the weird noises he emits. Dexter is freed by Titan to continue his 'good work'.

Investigating the disappearance of a robot probe, Stingray is drawn to the bottom of a volcano where two survivors of a destroyed city attempt to steal Stingray to escape the erupting volcano. When Marina locks the hatch they are forced to return for Troy and Phones who have been left to die. Since there are only two sets of breathing gear, Troy and Phones must rely on their WASP training to make the swim to Stingray.

Troy locks horns with the boastful Naval Captain who arrives in Marineville to demonstrate a new missile. X20, however, loads the test missile with real explosives and it appears that the Naval Captain is actually out to kill Troy. Shore is ready to Court Martial the Captain until Troy proves the interference of Titan's subjects.

While awaiting orders for a mission, Troy falls asleep. When he awakes, the Stingray crew are sent on the mission. Soon, they find themselves in a fish tank in a dining hall. The crew have shrunk! Titan and some underwater races have stolen plans for Marineville. Troy manages to call Commander Shore who doesn't believe their story, so the Stingray crew must come up with a plan to destroy the Marineville plans.

Following the destruction of a WASP submarine, Troy and Phones are sent to investigate. They are soon captured by an enemy submarine in the form of a gigantic fish, which takes them to the underwater city Titanica. There, they meet Titan for the first time.

The Stingray crew track the launch site of missiles fired on Marineville to a volcanic island. However, on investigating they become captured by the aliens responsible.

Commander Shore and Phones are taken prisoner by Idotee who uses an old Spanish galleon to attack ships. Shore demands that Troy launch Sting Missiles against the galleon but the Captain disobeys orders and boards the vessel. There he opens his air cyclinders in the control room but unknown to Idotee the cylinders are filled with laughing gas! The alien is laughing so hard he fails to realise that he's captured

The Stingray crew aid Professor Graham in his search for the missing temple of Tajmanon which was submerged when a dam was built in Africa. They encounter incredible dangers until they meet with El Hamra, an old colleague of Graham's who tells them that the temple was moved stone by stone to dry land.

Lt. Fisher takes command of Stingray in his training to become an Aquanaut. The exercise involves target practice on a Terror Fish target but X20 has attached a sticker bomb to one of the targets and one to Stingray's hull. Troy is air-dropped into the sea in an attempt to remove the bomb from Stingray's hull before it explodes.

Eastern despot El Hudat wants to become a member of the WASPs. Just as he is about to join up, there is a revolt in his country and he is ousted from power. Angered, he blames the WASPs. El Hudat has an interest in Marina, so the dictator kidnaps her and takes her aboard his yacht causing the Stingray crew to save her.

Following the escape of his slave Marina, Titan plots revenge by planning to kill the Stingray crew with a deadly plant that gives off toxic fumes. Meanwhile, Marina is feeling homesick.

Commander Shore keeps having nightmares when he was crippled in a sea battle with an underwater craft five years ago and rescued by a mysterious stranger.

The Solistan's want to take over the world by destroying the west coast of the USA with their attack sub.(big gun 1) Stingray destroys the sub before it can do any damage. Hungry for revenge, the Solistan's want to destroy Marineville so they launch Big Gun 2. Marineville survives & Stingray follows it back to it's deep sea base & with Marina's help they destroy the Solistan's.

A film crew arrive at Marineville to make a movie on Stingray. Everyone will play themselves except Troy, who is to be replaced by an actor. What's worse is that the director is in fact Surface Agent X20 who has a plan to kill Troy !!