The Salty Hippo
The Salty Hippo is a ship owned by Captain Blubber. Blubber crashes The Salty Hippo in Treasure Trove Cove and his treasure gets lost inside. Blubber abandons the ship after Banjo and Kazooie retrieve the treasure for him.
In Banjo-Tooie, there is a sunken ship located at the bottom of the lagoon in Jolly Roger Lagoon. This ship is believed to be The Salty Hippo, but in the Tower of Tragedy quiz game, there is a question that asks what the name of the ship is at the bottom of Jolly Roger's Lagoon, and the correct answer is "It has no name" and "The Salty Hippo" is incorrect. So the ship is probably not The Salty Hippo.