USS Gem during World War I
History
United States
Name	USS Gem
Namesake	Previous name retained
Builder	George Lawley & Son, Neponset, Massachusetts
Completed	1913
Acquired	26 March 1917
Commissioned	1 June 1917
Decommissioned	10 January 1919
Fate	Returned to owner 10 January 1919
Notes	Operated as private yacht Gem 1913-1917 and from 1919
General characteristics
Type	Patrol vessel
Tonnage	201 Gross register tons
Length	146 ft 6 in (44.65 m)
Beam	18 ft (5.5 m)
Draft	7 ft (2.1 m)
Propulsion	Steam engine
Speed	15 knots
Armament	2 × 3-pounder guns

USS Gem (SP-41) was an armed yacht that served in the United States Navy as a patrol vessel from 1917 to 1919.

Gem was built in 1913 as a private steam-powered yacht of the same name by George Lawley & Son at Neponset, Massachusetts. The U.S. Navy acquired her under charter from her owner, William Ziegler Jr., on 26 March 1917 for World War I service. She was commissioned as USS Gem (SP-41) on 1 June 1917 at New York City.

Gem performed harbor entrance patrol at New Haven, Connecticut, until 12 December 1917. She was then assigned to experimental work under the Submarine Defense Association. In this duty, carried out at New York City; New London, Connecticut; Newport, Rhode Island; and New Haven, she experimented with camouflage defense, tested the Bates Automatic Course Indicator, and experimented with various submarine detection devices, including the Sanborn Speed Indicator. She also performed colloidal fuel experiments with pulverized coal at New Haven and New York.

The Navy decommissioned Gem on 10 January 1919 and returned her to her owner the same day.

References

• 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: U.S. Navy Ships: USS Gem (SP-41), 1917–1919. Originally, and later, the Civilian Steam Yacht Gem (1913)
• NavSource Online: Section Patrol Craft Photo Archive Gem (SP 41)