Watchful was the privately-owned, 146-ton schooner Skylark that the Lighthouse Service purchased in 1856. She retained her original name until 1857 when she was renamed Watchful in April of 1857.
She remained in service at the 10th Lighthouse District until she was sold on 16 October 1867.
Dennis Noble. Lighthouses & Keepers: The U.S. Lighthouse Service and Its Legacy. Annapolis: Naval Institute Press, 1997.
Douglas Peterson. United States Lighthouse Service Tenders, 1840-1939. Annapolis: Eastwind Publishing, 2000.