DeSeve's scout ship
DeSeve's scout ship was a Romulan scout ship stolen by former Starfleet traitor turned Romulan defector, Ensign DeSeve in 2369.
DeSeve claimed to have spent two weeks alone in this scout ship, risking his life to return to the Federation, before arriving at Research Station 75. (TNG: "Face Of The Enemy")
This scout ship was only mentioned in dialogue.