[5] The ship was delivered to United States Lines to operate under charter with option to purchase from the Maritime Commission for operation on the New York, Baltimore, Philadelphia, Hampton Roads and Savannah direct cargo service to Manila, Shanghai and Hong Kong by their American Pioneer Line intended to be the fastest direct cargo service between the United States' East Coast and the Far East.

[10] Shortly thereafter Sea Witch successfully delivered fighter planes to Java in a failing effort to reinforce Allied forces there resisting the Japanese invasion of the Dutch East Indies.

[4][11] Sea Witch, with twenty-seven disassembled and crated P-40 fighters aboard, departed Fremantle, Australia on 22 February 1942 in Convoy MS.5 that was bound for Colombo, Ceylon with troops and supplies eventually destined for India and Burma.

[11][12][14] The two ships proceeded north separately, but Langley was attacked and sunk by Japanese land-based bombers on 27 February, despite being escorted by two American destroyers sent from Tilatjap.

[21] On 21 September 1943 Sea Witch departed Port Hueneme, California with over 1,000 officers and men of the 91st Naval Construction Battalion bound for Milne Bay, New Guinea and after a brief stop in Australia arrived on 21 October 1943 with the next five days spent unloading.

[22][note 2] Sea Witch was returned to the Maritime Commission 24 June 1946 and laid-up at James River Reserve Fleet having made her last voyage into the port of New York.