USS Niagara (SP-263) was a vessel of the United States Navy during World War I.

History
United States
Name	USS Niagara
Builder	E. A. Fonda, Miami, Florida
Launched	1915
Acquired	5 July 1917
Fate	Transferred to the United States Lighthouse Service, 29 May 1919
United States
Name	USLHT Poinsettia
Acquired	29 May 1919
Decommissioned	21 April 1922
Fate	Sold, 1922 Caught fire and sank, 27 December 1928
General characteristics
Type	Patrol boat / Lighthouse tender
Displacement	33 long tons (34 t)
Length	50 ft (15 m)
Beam	16 ft (4.9 m)
Draft	2 ft 9 in (0.84 m)
Propulsion	50 hp (37 kW) gasoline engine, one shaft
Speed	10.4 knots (19.3 km/h; 12.0 mph)
Complement	5
Armament	1 × 1-pounder gun 1 × machine gun

Niagara, a yacht built in 1915 by E. A. Fonda of Miami, Florida, was purchased by the United States Navy on 5 July 1917 from General H. M. Creel, of Miami, and was designated USS Niagara (SP-263). The navy redesignated the boat as SP-263 on 11 April 1918, dropping the name Niagara.

After the war, on 29 May 1919, she was transferred to the United States Lighthouse Service, converted into a lighthouse tender and rechristened USLHT Poinsettia. She was assigned to the 7th Lighthouse District in Key West, Florida.

Poinsettia was decommissioned on 21 April 1922 at the Philadelphia Navy Yard and was sold. She caught fire and sank on 27 December 1928.