Nemo and crew save a Killer Whale trapped under a cable.
Chris and Robbie accidentally become involved in a battle between a giant squid and a sperm whale.
The Nautilus intervenes to save a herd of singing Humpback whales from brutal poachers.
The Nautilus must act quickly to keep a herd of Pilot Whales from beaching themselves.
Chris is forced to pioneer a new shark repellent device.
Eels become a danger to the Nautilus when it accidentally intrudes on their grounds.
The crew of the Nautilus explore the strange life in the Sargasso Sea.
Nemo rescues Robbie when an experiment with sharks gets out of hand.
The Nautilus faces a dangerous WWII magnetic mine.
The Nautilus finds sunken treasure, but it is guarded by vicious Moray eels.
An experimental Sea-gold refining ship is attacked by pirates.
An ingenious but illegal way to harvest fish is foiled by the crew of the Nautilus.
A wealthy collector who illegally bombs fish to add to his collection, has the tables turned on him.
The Nautilus is trapped by an undersea volcano.
The Nautilus is lost in an underwater labyrinth.
Mining Manganese nodules becomes hazardous when the kids' mini-sub becomes disabled.
An oil rig's submersible repair craft is trapped under the rig during a storm.
Observing the chaos of the food chain from an open boat becomes dangerous.
On a snowmobile exploration of the Arctic the crew of the Nautilus must race a Polar Bear to reach safety.
The Nautilus saves an injured dolphin from a ravenous pack of sharks.
Specially trained dolphins guarding a bathing beach, fight off sharks.
Only a dolphin can get to the surface and back with support gear fast enough to save a diver.
The Nautilus becomes a life jacket for an injured whale.
The crew of the Nautilus investigates the monsters that live in the deeper parts of the sea.
During an experiment, Robbie has to ward off a hungry Hammerhead Shark with his bare hands.
Trapped in treacherous coral reefs with an monsoon approaching, Robbie and Chris have to think quickly to save the Nautilus.
A search for ghosts leads to ruins of Carthage.
A Sea Leopard stalks the crew of the Nautilus under the ice.
Mysterious thefts of cultured pearls at an oyster farm.
Lava from a volcano menaces an Icelandic village and only the Nautilus stands in its path.
Robbie goes after a Coelecanth and develops Nitrogen Narcosis when he goes too deep.
The Nautilus investigates a case of deliberate pollution and encounters the largest shark in the world.
An emergency forces the Nautilus to hijack an iceberg.
What is the secret of the ancient gold coins found by the islanders?
The Nautilus tries to recover a cargo of valuable medicine from a sunken ship full of explosives.
A mysterious force pulls Chris helplessly into a cave full of sharks.
A diver is pinned under a container that holds radioactive materials.
The crew of the Nautilus is honored by the Save the Whale foundation.
Trained Killer Whales display their abilities.
A giant squid menaces the recovery of a group of astronauts.
The Nautilus investigates the Bermuda Triangle.
Mating Sea Snakes complicate the retrieval of a meteorite.
Robbie has an encounter with a fatal Sea Wasp.
The Nautilus takes a look at some of the strangest sharks in the world.
A small plane goes down in a lake in the middle of the ocean.
Mark, Chris and Robbie save a rare Leatherback turtle.
A plague of starfish descend on an oyster bed.
The crew of the Nautilus sees the results of man's effect on his environment.
While testing new thermal diving suits in the Arctic, Robbie and Chris lose their way under the ice.
Why is Mark sending the Nautilus on a collision course with an island?
Poachers hunting the protected Right Whale are pursued by the Nautilus.
The hunter becomes the hunted when the Nautilus, trapped in an underwater landfall, is at the mercy of desperate diamond thieves.
It's a bad time for Robbie's radio to break down when he gets his foot caught in a giant clam.
The Nautilus creates its own whirlpool to save a kelp farm.
Mark, Robbie and Chris turn into ghost hunters at a haunted sea lab.
Help comes from an unexpected source when the crew of the Nautilus is menaced by walruses.
Teenagers swimming near a nuclear power plant develop a strange glow.
Mark makes his acting debut to save the Hawksbill turtle.
Tables are turned when Chris is saved by a dolphin.
Man-eating Leopard Seals menacing a colony of penguins.
Robbie and Chris look for mermaids off the Florida Keys.
A Swordfish attacks the Minisub with Chris and Robbie inside.
The crew of the Nautilus discover the world's only bullet-proof fish.
Robbie is sure he and Chris have found the Loch Ness Monster.
Danger still lurks in the graveyard of World War 2 ships.
Study of the Remora fish takes the Nautilus into the middle of a school of sharks.
The Nautilus crew discovers treasure worth millions of dollars.
A fleet of whaling ships find themselves mysteriously sealed up in the middle of an iceberg.
The crew of the Nautilus discover a plan to save the Sea Turtle.
Things are seldom what they seem, under the ocean.
Millions of poisonous sea snakes are sighted off the coast of a Jamaican resort.
Robbie is almost taken for a tuna when he stumbles into some fishing nets.
Mark shows Chris and Robbie the secrets of hidden marine life.