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The Luxo Cruiser is Greevil's personal yacht in Pokémon XD.
It is first seen in Gateon Port, docked near the rotating bridges. Later, Greevil along with Ardos and Eldes sail on it to Citadark Isle, where it remains permanently.
A Sailor inside Citadark Isle's headquarters mentions that Greevil makes him 'swab the decks' of the Luxo Cruiser. He also reveals that Greevil rarely leaves it when he visits Citadark Isle.