USS APc-21 was a United States Navy APc-1-class small coastal transport vessel in World War II. Laid down on 24 May 1942 as Coastal Minesweeper AMc-173 at Hodgdon Brothers, and Goudy and Stevens, East Boothbay, Maine, she was launched on 2 September 1942 and commissioned as APc-21 on 27 February 1943.^[1]

Small Coastal Transport APc-1 class
History
United States
Name	USS APc-21
Builder	Hodgdon Brothers, Goudy and Stevens, East Boothbay, Maine
Laid down	24 May 1942, as a coastal minesweeper AMc-173
Launched	2 September 1942
Commissioned	27 February 1943, as APc-21
Fate	Sunk, 17 December 1943
General characteristics
Class and type	APc-1 class small coastal transport vessel
Displacement	100 long tons (102 t) light 234 long tons (238 t) full load
Length	103 ft (31 m)
Beam	21 ft 3 in (6.48 m)
Draft	9 ft 3 in (2.82 m)
Propulsion	1 × 400 shp (298 kW) Atlas 6HM2124 diesel engine 1 × shaft
Speed	10 knots (19 km/h; 12 mph)
Complement	25 (3 officers, 22 enlisted)
Armament	4 × single 20 mm AA gun mounts
Service record
Part of:	Amphibious Force Seventh Fleet
Operations:	Battle of Arawe

She sailed from Maine to Brisbane, Australia and served with the Seventh Fleet Amphibious Force in the South West Pacific Area conducting operations off the coast of New Guinea. She was participating in the landings during the battle of Arawe when struck by a bomb from an enemy air attack off Arawe, New Britain on 17 December 1943 and sank within four minutes.^[1]

Wreck location: 6°14′57″S 149°0′53″E / 6.24917°S 149.01472°E / -6.24917; 149.01472^[2]