Elf (SP-81) as a civilian motorboat on a winter day in early 1917, just after her completion and prior to her U.S. Navy service
History
United States
Name	USS Elf
Namesake	Previous name retained
Builder	Stanley Vansant
Completed	1917
Acquired	May 1917
Commissioned	3 May 1917
Decommissioned	9 January 1919
Fate	Returned to owner 10 January 1919
Notes	Operated as private motorboat Elf 1917 and from 1919
General characteristics
Type	Patrol vessel
Length	53 ft (16 m)
Beam	12 ft (3.7 m)
Draft	3 ft (0.91 m) mean
Speed	22 knots
Complement	8
Armament	1 × 1-pounder gun

USS Elf (SP-81) was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1919.

Elf was a civilian motorboat completed in early 1917 by Stanley Vansant. In early May 1917, the U.S. Navy acquired her under a free lease from her owner, Louis H. Eisenlohr of Philadelphia, Pennsylvania, for World War I service as a patrol boat. She was commissioned as USS Elf (SP-81) on 3 May 1917.

Elf performed patrol duty in the 4th Naval District until July 1918, when she was transferred to the 7th Naval District.

Elf was decommissioned on 9 January 1919 and returned to her owner on 10 January 1919.

•  This article incorporates text from the public domain Dictionary of American Naval Fighting Ships. The entry can be found here.
• Department of the Navy: Naval Historical Center: Online Library of Selected Images: Civilian Ships: Elf (American Motor Boat, 1917). Served as USS Elf (SP-81) in 1917-1919
• NavSource Online: Section Patrol Craft Photo Archive: Elf (SP 81)