PT-117 was an 80-foot Elco motor torpedo boat, built at the Elco works in Bayonne. She was laid down on 10 April 1942, launched on 15 July, and placed in service on 4 August. She went to Motor Torpedo Boat Squadron 6. Men called her Munda Morn. On 29 August she lay alongside PT-124 and the destroyer Saufley in New York, the day Saufley was commissioned.
On the night of 23 July 1943 she was on patrol in Blackett Strait, west of Vila, with two other boats. Barges were there, and destroyers. They were gone before the boats closed to a range where they could fire. No hit is claimed for her that night.
On 1 August 1943 Japanese aircraft struck the boats in Rendova harbor. A bomb opened her bow and she was beached there. She was at the base that day. She was not in Blackett Strait with the boats that went out that night. Which of the bombs that fell on the harbor hit her is not pinned.