Season 3
All Episodes
Episode 1
The Siphonophore
September 4, 2013
Kwazii and Dashi become entangled in a strange deep-sea creature - a siphonophore.
Episode 2
The Water Bears
September 5, 2013
The gang ventures into a red-hot lava tube to rescue a tiny water bear that does not seem to mind the heat at all.
Episode 3
The Cone Snail
September 6, 2013
Peso sets out to save the day when a cone snail invades the octopod and picks off the crew one by one with its dangerous harpoons.
Episode 4
The Artificial Reef
September 9, 2013
When an underwater storm destroys a small reef, Tweak and her crew try to convert the Gup-F into an artificial equivalent.
Episode 5
The Humpback Whales
September 10, 2013
When a sardine swallows the key to a treasure chest, a humpback whale helps Kwazii track it down.
Episode 6
The Pelicans
September 11, 2013
When a floating garbage patch endangers a flock of pelicans and other sea creatures, the Octonauts and the birds work together to clean it up.
Episode 7
The Sea Pigs
September 12, 2013
The Octonauts must stop a huge herd of sea pigs before they march blindly into the Mariana Trench - where there will be no access to food. But things get chaotic when Tunip goes missing!
Episode 8
The Yeti Crab
September 13, 2013
As Tweak tests the Gup-X deep down in the Midnight Zone, a yeti crab cuts a vital electrical wire in the ship and cuts off all power, endangering itself and the Octonauts.
Episode 9
The Barracudas
March 10, 2014
Shellington and the Vegimals' mission to replant a mangrove forest is put in peril by a school of toothy barracudas.
Episode 10
The Duck-Billed Platypus
March 11, 2014
While rescuing river creatures after a storm, the Octonauts find a strange egg and come under attack by stinging platypuses.
Episode 11
The Sea Skaters
March 12, 2014
When Kwazii gets lost at sea aboard the tiny octo-ski, he meets a flotilla of even tinier sea skaters - the only insects who live on the ocean.
Episode 12
The Mudskippers
March 13, 2014
The Octonauts attempt to keep the peace amongst a trio of mudskippers whose home has been flooded.
Episode 13
The Harbour Seal
March 14, 2014
When Peso's patient, a remora fish, mysteriously disappears, the Octonauts enlist a unique undersea detective - a harbour seal.
Episode 14
The Lion's Mane Jellyfish
March 17, 2014
A lion's mane jellyfish gets its long and stingy tentacles tangled in the bubble engine, unintentionally flooding the Octopod and causing havoc.
Episode 15
The Red Rock Crabs
March 18, 2014
When Shellington and the crew try to gather some skittish crabs who have drifted away from home, they get help from some old friends.
Episode 16
The Sea Sponge
March 19, 2014
A sea sponge that houses other sea creatures in its pores suffers from a mysterious illness and Peso must figure out the cause.
Episode 17
The Immortal Jellyfish
March 20, 2014
Shellington and the Octonauts try to track an unusual creature: a jellyfish that can transform from old to young repeatedly - and live forever!
Episode 18
The Urchin Invasion
March 21, 2014
The Octonauts head to the kelp forest to visit Shellington's sister, Pearl, and her newborn son Periwinkle - only to find the forest endangered by an infestation of kelp-eating urchins!
Episode 19
The Hammerhead Sharks
September 21, 2015
The Octonauts meet some hammerheaded sharks, however, they can't sleep too well because Shellington and Professor Inkling have been arguing about who is smarter that they are no longer friends.
Episode 20
The Loggerhead Sea Turtle
September 22, 2015
After an undersea tremor separates the Gup-X and its crew, Barnacles seeks guidance from a mysterious sea turtle.