From June 1965 to March 1966 the USNS Saugatuck, was operated under MSTS contract by Keystone Shipping Company of Philadelphia, PA. During this period she continued to carry petroleum products from the US West Coast to United States Naval bases and depots in the Pacific, including Pearl Harbor, Hawaii, Midway, Wake & Kwajalein Islands, as well as, four (4) months of "floating storage" duty in Cham Ranh Bay & Da Nang, Vietnam from August through December 1965. On completing this duty she spent 2 weeks in the US Naval Shipyard Subic Bay, Philippines. Then continued west bound to Ras Tanura, Saudi Arabia, the Suez Canal, Greece, & Spain, before returning to the US East Coast ports of Delaware City & Providence, RI.