CSS Birmingham

The CSS Birmingham was, orignally, a Confederate Ironclad warship sunk at the bottom of the sea, until the war god Ares raised it from the depths so Clarrise may have transporation and a crew to escort her.

Sea of Monsters
Ares raised the Birmingham to serve Clarisse La Rue in her quest because, as Clarrise explained, the losing side of any war owed a dept to Ares. After rescuing Percy Jackson and Annabeth Chase from a Hydra attack, the ironclad departs for the Sea of Monsters, otherwise known to mortals as, you guessed it, the Bermuda Triangle. The Birmingham was later sunk by Scyllia and her sister, but Percy, Annabeth, and Clarrise escape in the nick of time. Percy and Annabeth wash up on the shores of Circe's Island, while Clarrise ends up in Polyphemus's island.