After training and exercises off the California coast, "Muskogee", manned by a United States Coast Guard crew, departed San Pedro, California, on 18 June 1944, for Nouméa, New Caledonia, where she arrived on 18 July 1944, for patrol and escort duty from Nouméa and, after its capture, Humboldt Bay, New Guinea. Anti-submarine patrol and screening for ships operating around New Guinea were her primary duties into October 1944. On 18 October 1944 she got underway screening the second reinforcement group bound for newly invaded Leyte in the Philippine Islands, arriving in San Pedro Bay on 24 October to screen transports and supply ships under numerous Japanese air attacks while waiting for a group of empty tank landing shipss to form up for the return passage. As her convoy retired on 26 October 1944, Japanese aircraft again attacked it, and "Muskogee" joined in downing several enemy aircraft. A second escort voyage to Leyte in early November 1944 was less eventful.