USS YP-399 was a fishing vessel acquired by the U.S. Navy before completion during World War II to serve as a patrol boat.
She was completed in 1942 at the Tacoma shipyard of the Peterson Boat Building for the benefit of John Brescovich and named Big Dipper.[1] [2] On 29 May 1942, she was acquired by the U.S. Navy.[1] She was designated as a Yard Patrol Craft (YP) and assigned to the 13th Naval District.[2] Her commanding officer was Lieutenant Commandeer Vernon Johnson.[2] She was one of the initial ships assembled by Captain Ralph C. Parker for the Alaskan Sector, Northwest Sea Frontier, 13th Naval District[2] colloquially known as the "Alaskan Navy".
On 8 May 1946, she was struck from the Naval List and transferred to the United States Maritime Administration who returned her to her original owner.[1] She served as a commercial fishing vessel thereafter for a number of owners under the names Big Dipper (until 1951), FV Liberty Bell II (until 1967), and FV Nautilus.[3] She went out of registration in 1997.[3]