The Octonauts - Season 3

In the third season of the series, an underwater storm destroys small reefs. Now, Tweak and her crew are trying to turn Gup-F into a synthetic equivalent to get things back up again. The sardines swallow the key to the treasure chest, as the humpback whale as a hen is tracking them before it is too late. There is still a real danger due to the floating litter patch, which endangers the life of a group of swans and other marine creatures.