Endless Ocean

Unlike in the similar Aquanaut's Holiday, only a small area of the full game world is seamlessly accessible at any one time. Diving tours are limited to a certain area around the player's boat, which can be freely moved about a map of the whole game world. This allows the player to choose for themselves the area of the game world they can access without having to bear loading times; however it is not possible to move from one play area to another without returning to the boat and using the map to move it around.

The game keeps track of the species of animals encountered and examined in three levels of detail - no information and three small pieces of information on each species. The animals are mostly marine life - fish, dolphins, whales, sea lions - but also include various coastal and marine birds, such as penguins and pelicans. There are a number of extra features that unlock during the first few hours of gameplay, including night diving, an underwater camera/photo album and an aquarium the player can populate with species of animals they've encountered in the open sea.

This title also adds online multiplayer to the series, allowing for players to use Nintendo's WFC service to go diving together. The game does not use the Wii system's built-in friend code but instead generates its own, requiring players to keep a separate friend list for the game.