第 4 季 共 24 集
播出时间：2015年9月30日
第 1 集 Octonauts and the Walrus Pups
播出时间：2015年9月30日
When a giant wave hurls Amazon River creatures up into the trees, the Octonauts must get them down safely, without disturbing poison dart frogs who live there.
第 2 集 Octonauts and the Mantis Shrimp
播出时间：2015年10月1日
The Octonauts are exploring Antarctica, when Shellington discovers strange microscopic creatures living under the ice.
第 3 集 Octonauts and the Poison Dart Frogs
播出时间：2015年9月24日
When the Octopod breaks down, Tweak and the crew search for a missing part aboard an abandoned prototype of the ship, not realising something lives there.
第 4 集 Octonauts and the Hidden Lake
播出时间：2015年9月25日
As newborn baby sea turtles make their way to the ocean, the Octonauts must steer them clear a giant wave and hungry predators.
第 5 集 Octonauts and the Baby Sea Turtles
播出时间：2015年9月29日
Captain Barnacles and his niece and nephew, Ursa and Orson, must rescue walrus pups who are stranded on a runaway ice floe, before it collides with a huge iceberg!
第 6 集 Octonauts and the Octopod Mystery
播出时间：2015年9月26日
The Octonauts must get 2 mantis shrimp to stop fighting before their powerful claw strikes destroy the Octopod.
第 7 集 Octonauts and the Tree Lobsters
播出时间：2015年10月3日
The Octonauts follow a strange song to a lonely humpback whale.
第 8 集 Octonauts and the Convict Fish
播出时间：2015年12月15日
When a storm washes Peso onto a mysterious, rocky island, he meets a band of lobster-like insects thought to be extinct.
第 9 集 Octonauts and the Crawfish
播出时间：2016年12月4日
The Octonauts evacuate the creatures living around a reef before a large archway collapses, but one stubborn convict fish refuses to move from her burrow.
第 10 集 Octonauts and the Surfing Snails
播出时间：2017年9月7日
The Octonauts journey across a dangerous expanse of ice to help a penguin mother get back to her family.
第 11 集 Octonauts and the Baby Gator
播出时间：2017年10月27日
Kwazii adopts a baby alligator naming him Nipper, but when it escapes the Octopod, he and the Octonauts must rescue him.
第 12 集 Octonauts and the Bomber Worms
播出时间：2017年10月24日
While diving down to the Midnight Zone, the Octonauts are attacked by bomber worms.
第 13 集 Octonauts and the Flamingos
播出时间：2016年12月5日
When a population of crawfish is stricken by illness, the Octonauts race to find a cure.
第 14 集 Octonauts and Operation Cooperation
播出时间：2017年9月28日
When surfing snails are swept out to sea, it's up to Dashi and the Octonauts to save them.
第 15 集 Octonauts and the Kelp Monster Mystery
播出时间：2017年10月25日
The Octonauts find a lost flamingo chick separated from his family and they have to return him there before hungry alligators do!
第 16 集 Octonauts and the Hippos
播出时间：2017年9月21日
After Shellington crashes the GUP-D for the 3rd time, he and Kwazii team up with moray eels and grouper fish to help pick up the pieces and fix the vehicle before daylight occurs.
第 17 集 Octonauts and the Yellow Bellied Sea Snakes
播出时间：2017年9月14日
Dashi teams up with her little sister Koshi to help the Octonauts solve a mysterious disappearance in the Kelp Forest. This is the second episode in which is unknown who sounded the Octo-Alert.
第 18 集 Octonauts and the Loneliest Whale
播出时间：2015年10月2日
When Peso gets stranded on a beach with a mass of poisonous snakes after a terrible storm, he and the Octonauts must somehow get them back to the ocean.
第 19 集 Octonauts and the Spinner Dolphins
播出时间：2017年10月28日
Kwazii takes a vacation on Coconut Island where he gets hit by some coconuts. Then he and the Octonauts must help their old friends the Coconut Crabs discover who's stealing all their coconuts.
第 20 集 Octonauts and the Coelacanth
播出时间：2017年5月30日
While exploring a dark and spooky cave, The Octonauts find a strange fossil of a powerful prehistoric fish... but it may be more than just a fossil!
第 21 集 Octonauts and the Emperor Penguins
播出时间：2015年12月17日
When a hungry tiger shark eats the camera that Tweak's turtle friend Sandy gets in the Octopod, she and the Octonauts must rescue her before it eats everything in its path.
第 22 集 Octonauts and the Tiger Shark
播出时间：2017年5月28日
Trying to return home from a mission along an African river, the Octonauts have trouble getting past a gang of large, mud-splatting, territorial hippos.
第 23 集 Octonauts and the Coconut Crisis
播出时间：2017年10月26日
The Octonauts struggle to save a pod of spinner dolphins who seem to be just swimming in their sleep.
第 24 集 Octonauts and the Sunfish
播出时间：2017年5月29日
When a huge sunfish enters the GUP-E, Peso and Kwazii must somehow get the large fish out of the Gup. Eventually they find out it's a Sunfish a fish with no fins.
