The USS Seaquest was a 24th century Federation starship operated by Starfleet.

Darien Wallace was assigned on stardate 42983.6 to this ship, which was named on his personnel file. (TNG: "Eye of the Beholder", okudagram)

This starship was only mentioned in writing.
There was some question as to the existence of the Seaquest, since all of the personnel files displayed were part of Deanna Troi's hallucination (and thus might not be real). Its name was a homage to the science fiction series seaQuest DSV. [1]