An old Altru Inc. oil rig has polluted the Sea of Wailord with scrap metal and various other pieces of junk, further complicating navigation of its waters. Surprisingly, many Pokémon still manage to live here despite these conditions. The Team Dim Sun Marine Unit placed beam generators that captured a Wailord here, which they wanted to use to replace the cargo ship that the player broke down before. After the player puts a stop to their plans, they take a Wailmer instead, deciding to bluff their way through and call it a "Wailord mini." The Wailord becomes very agitated and it takes the player to the oil field hideout, where the player finds Sven. Together the player and Sven must investigate the hideout and free the Wailmer.
The four beam generators that imprison the Wailord require a level 3 Crush target clear.
The player also returns to the Sea of Wailord to capture an Omastar for the angler in Pueltown as part of an optional quest.