The Octonauts and the Sea of Shade Other Books in This Series

The Octonauts and the Great Ghost Reef The Octonauts and the Great Ghost Reef
The Octonauts and the Great Ghost Reef
2009
The Octonauts and the Frown Fish The Octonauts and the Frown Fish
The Octonauts and the Frown Fish
2008
The Octonauts and the Only Lonely Monster The Octonauts and the Only Lonely Monster
The Octonauts and the Only Lonely Monster
2014