Episode Number

1 "Octonauts and the Whale Shark"  (2010-10-04)
When Dashi is swallowed by a whale shark she thought was a cave, the Octonauts venture inside it to rescue her.
2 "Octonauts and the Undersea Storm"  (2010-10-05)
Kwazii's Gup-B crashes while trying to outrun a storm. When the GUP-C's tow-rope snaps while rescuing him, some Reef Lobsters Kwazii had helped reach shelter lend a hand before the storm gets there.
3 "Octonauts, the Crab, and the Urchin"  (2010-10-06)
A Carrier Crab and the urchin it keeps on top of its shell as a defence against predators have a falling out.
4 "Octonauts and the Walrus Chief"  (2010-10-07)
A walrus mistakes Peso's medical bag for a clam and takes it home. Walruses don't like other animals near their colonies, so Captain Barnacles, Kwazii and Peso disguise themselves as a fellow walrus to sneak into the dangerous colony and retrieve the medical bag.
5 "Octonauts and the Flying Fish"  (2010-10-08)
A school of flying fish accidentally make off with Professor Inkling's rare book.
6 "Octonauts and the Giant Squid"  (2010-10-11)
The Octonauts set out to find and photograph Inkling's long lost cousin, the giant squid.
7 "Octonauts and the Orcas"  (2010-10-12
An enormous Orca whale is stranded on a beach, and with some help from some crabs, the Octonauts manage to rescue it.
8 "Octonauts and the Great Algae Escape"  (2010-10-13)
The crew must catch a runaway Octopod after it is hijacked by a group of crustaceans who are trying to flee an area of seabed being polluted by a broken pipeline.
9 "Octonauts and the Remipedes"  (2010-10-14)
Shellington goes to search for a group of Remipedes in a cave but he hasn't driven the GUP-D before and ends up crashing it and breaking it. The other Octonauts try to save him but they get lost too. Luckily, a group of blind Remipedes help them find their way out of the cave.
10 "Octonauts and the Speedy Sailfish"  (2010-10-15)
Barnacles and Kwazii use the Gup F to catch the gups, some help from some Sailfish also to round up all the runaway Gups.
11 "Octonauts and the Blobfish Brothers"  (2010-10-18)
The Octonauts must evacuate some slow moving, gelatinous Blobfish before an undersea volcano erupts.
12 "Octonauts and the Monster Map"  (2010-10-19)
Kwazii has a pirate map showing the location of a sunken treasure ship which allegedly harbours a Kracken-like sea monster (but which turns out to be an octopus which can change color to camouflage itself).
13 "Octonauts and the Lost Sea Star"  (2010-10-20)
Searching for the home of a lost Sea Star, the Octonauts crash-land in the Midnight Zone, having met Brittle Stars and a Sunflower starfish on the way down.
14 "Octonauts and the Albino Humpback Whale"  (2010-10-21)

The Octonauts think they've seen a ghost, but it turns out to be an albino Humpback Whale which is moaning from the pain of some nasty sunburn.

15 "Octonauts and the Giant kelp Forest"  (2010-10-22)
Kwazii's favorite sub, the Gup B, goes missing in a huge kelp forest due to Kwazii pressing the eject button while the engine was active (Something Tweak advised him not to do) and the Octonauts must retrieve it.
16 "Octonauts and the Enemy Anemones"  (2010-10-25)
The Octonauts land on an island for a picnic but must first help some crabs trapped between two Anemones. Meanwhile back on the Octopod, a hoard of out of control puddings are attacking.
17 "Octonauts and the Narwal"  (2010-10-26)
Cruising underwater to Captain Barnacles' homeland, the North Pole, the Octopod gets trapped in the Artic sea ice. But one of Barnacles' old friends, Boris the Narwhal, helps them to break through the ice with his long tusk.
18 "Octonauts and the Midnight zone"  (2010-10-27)
The Octonauts explore the deepest part of the ocean where no daylight ever reaches and find some hydrothermal vents where vent fish, limpets and tube worms live, and also discover a new species of worm to put in Shellington's book.
19 "Octonauts and the Snapping Shrimp"  (2010-10-28)
A little shrimp with a big claw makes such a loud noise that it stuns the Octonauts. A video of it made by Dashi reveals that the sound and accompanying shock wave are caused by the shrimp makng a giant bubble with its claw.
20 "Octonauts and the Snot Sea Cucumber"  (2010-10-29)
An injured snot sea cucumber named Slippy gets loose on the Octopod, so to let her breathe, they flood the ship.
21 "Octonauts and the Giant Whirlpool"  (2010-11-01
The Octonauts race against time to rescue Tweak's pal, a Leatherback Sea Turtle named Sandy, when she is swept away from the Australian coast where she was about to lay her eggs.
22 "Octonauts and the Hermit Crabs"  (2010-11-02)
With half the crew stranded in a rock pool due to a low tide, Peso and Tweak help to remove a stuck Hermit Crab from its shell.
23 "Octonauts and the Mixed Up Whales"  (2010-11-03)
The Octonauts clean and repair their ship, the Octopod, but discover that creaking noises from the Octopod are confusing two Blue whales who are looking for each other.
24 "Octonauts and the Kelp Forest Rescue"  (2010-11-04)
Peso's little brother Pinto visits the Octonauts and gets an eyepatch from Kwazii. He becomes more interested in being a pirate than a medic (stating that he wanted to be a 'real' Octonaut like Kwazii). But when he helps Barnacles, Kwazii and Peso in a mission to help Dashi and Shellington escape, he begins to like being a medic.
25 "Octonauts and the Decorator Crab"  (2010-11-05)
The Octonauts stake out a thief, who turns out to be a decorator crab.
26 "Octonauts and the Beluga Whales"  (2010-12-06)
The Octonauts lead a pod of Beluga Whales stuck under the pack ice to safety by getting them to follow Peso while he's playing the same tune as the Beluga's song on his xylophone.
27 "Octonauts and the Hungry Pilot Fish"  (2010-12-07)
The Octonauts are chased by a whitetip shark only to discover all it really needed was a pilot fish to clean its teeth, and it just so happens that they have just met a lonely pilot fish that is hungry for action.
28 "Octonauts and the Vampire Squid"  (2010-12-08)
On a solo training dive to the Midnight Zone, Peso encounters a hurt vampire squid. Scared by the sudden arrival of Kwazii and Captain Barnacles it sprays them with sticky bioluminescent mucus and flees, but in the end Peso is able to help it.
29 "Octonauts and the Seahorse Tale"  (2010-12-09)
After a storm, the Octonauts help a female seahorse search for her missing mate. She tells them to Kwazii's surprise that the missing male seahorse is about to give birth.
30 "Octonauts and the Giant Jelly"  (2010-12-10)
The Octonauts must rescue Peso when he gets trapped inside a giant Comb Jelly.
31 "Octonauts and the Cookiecutter Sharks"  (2010-12-13)
A trio of pesky Cookiecutter Sharks make holes in the Octonauts' equipment.
32 "Octonauts and the Oarfish"  (2010-12-14)
Dashi catches a glimpse of an elusive creature that appears to be a giant sea serpent and manages to photograph its tail.
33 "Octonauts and the Combtooth Blenny"  (2010-12-15)
Kwazii crashes the GUP-E, leaving him and Peso on an island. Their SOS message to the Octonauts is relayed in increasingly garbled form via the Blenny, a bluefish, a squid, and an Anglerfish.
34 "Octonauts and the Jellyfish Bloom"  (2010-12-16)
Shellington gets trapped by sea nettle jellyfish whilst observing garden eels in the GUP-E. Barnacles, Kwazii and Peso attempt to save him but Barnacles gets stung by a jellyfish. Luckily, Peso heals it using vinegar and then goes to save Shellington along with Kwazii.
35 "Octonauts and the Baby Dolphin"  (2011-12-29)
A young dolphin follows Kwazii home and the Octonauts must search for its mother.
36 "Octonauts and the Scary Spookfish"  (2011-01-29)
Peso gets jammed in an ocean trench when the GUP-E's battery dies and is surprised by a strange deep sea fish with a transparent head: a Spookfish named Boo, whose ability to see vertically comes in handy as GUP-C winches GUP-E back up the narrow trench.
37 "Octonauts and the Artic Orcas"  (2011-01-25)
Captain Barnacles and Peso get lost in the icy Arctic sea when the GUP-E gets stuck in an iceberg and the gup finder is damaged.
38 "Octonauts and the Slime Eels"  (2011-01-26)
In the Artic, Kwazii searches the sunken shipwreck of his pirate grandfather, Calico Jack, for his gold spy glass. It's guarded by blind hagfish (slime eels), but their slime unexpectedly helps him when he gets stuck. Kwazii ends up leaving the spyglass because it's now the home of sea creatures.
39 "Octonauts and the Enormous Elephant Seal"  (2011-01-27)
An enormous Elephant seal is brought into the Octopod to moult as moulting underwater is dangerous.
40 "Octonauts and the Sardine School"  (2010-01-29)
The Octonauts must work together as a team to help a lost sardine find her school.
41 "Octonauts and the Dolphin Reef Rescue"  (2011-01-31)
Peso and the gang try to cure sick areas on a coral reef by transplanting healthy coral, but a pod of playful dolphins make mischief for them until they realise that helping can be fun too.
42 "Octonauts and the Eel Ordeal"  (2011-02-01)
The Octonauts help a injured migrating swamp eel on his difficult journey when he gets stranded from the others.
43 "Octonauts and te Mrine Iguanas"  (2011-02-02)
The team are preparing for a feast of red seaweed on an island but a trio of salt-sneezing Marine Iguanas raid the Octopod and eat it all.
44 "Octonauts and the Dwarf Lanternshark"  (2011-02-03)
The Octonauts must help a tiny, injured Dwarf Lanternshark, but they have to find him first.
45 "Octonauts and the Pirate Parrotfish" (2011-02-04)
When the Octonauts go on a pirate treasure hunt, Kwazii meets a Parrotfish, who helps them when they encounter some moray eels.
46 "Octonauts and the Electric Torpedo Rays"  (2011-02-07)
Some electric torpedo rays give the Octopod a jump-start when its batteries go flat after Adolf Hitler used the Battery Drainer 2000 during a trip to see Tweak's pal, Sandy the leatherback sea turtle.
47 "Octonauts and the Crafty Cuttlefish"  (2011-02-08)
Captain Barnacles allows Tunip to use his Octo-compass. But when Tunip loses it, a Cuttlefish takes it.
48 "Octonauts and the Lost Lemon shark"  (2011-02-09)
The Octonauts look after a Lemon Shark who has hurt his nose and can't find his way home.
49 "Octonauts and the Humuhumunukunukuapua'a"  (2011-02-10)
The Octopod's waterworks become flooded with frightened Humuhumunukunukuapua'a fish.
50 "Octonauts and the Giant Spider Crab"  (2011-02-11)
The Octonauts help a 100-year-old spider crab which has got its leg trapped in a giant clam while in route to its own 100th birthday party. It turns out that Kwazii's afraid of spiders, but he still helps, even though he thought it was a real spider at first.