Captain's yacht

The captain's yacht was a type of auxiliary vessel that was installed aboard several classes of Federation starships in the 24th century, including the Galaxy and Sovereign classes. On both designs, the yacht is launched from the underside of the saucer section, and was used by the ship's captain to travel alone or to host visiting dignitaries.

While Captain Jean-Luc Picard commanded the USS Enterprise-D didn't use the yacht in his eight years in command. This trend continued during his command of the USS Enterprise-E, while rarely using the yacht, he lost the Cousteau following a Son'a attack in 2375, and the Calypso was stolen by the Androssi in 2378. (TNG movie: Star Trek: Insurrection and novel: A Time to Be Born).