Captain's yacht

A captain's yacht is a type of auxiliary vessel that was installed aboard several classes of Federation starships in the 24th century, including the Galaxy, Pendragon and Sovereign classes. Typically, 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 aboard the USS Enterprise-D, Captain Jean-Luc Picard rarely used the yacht (called Calypso) during his eight years in command. This trend continued during his command of the USS Enterprise-E. He lost the Cousteau following a Son'a attack in 2375, and the Calypso II was stolen by the Androssi in 2378. (Star Trek: Insurrection; TNG novel: A Time to Be Born).

The yacht aboard the USS Pendragon was named Taliesin, and like Picard, Captain Timothy Sinclair rarely made use of the vessel. (Star Trek: Pendragon)