Speed 16 k
The second Cyclops, a collier, was launched 7 May 1910 by William Cramp and Sons, Philadelphia, Pa., and placed in service 7 November 1910, G. W. Worley, Master, Navy Auxiliary Service, in charge. Operating with the Naval Auxiliary Service, Atlantic Fleet, the collier voyaged to the Baltic during May to July 1911 to supply 2d Division ships. Returning to Norfolk, she operated on the east coast from Newport to the Caribbean servicing the Fleet. During the troubled conditions in Mexico in 1914 and 1916, she coaled ships on patrol there and received the thanks of the State Department for cooperation in bringing refugees from Tampico to New Orleans.
With American entry into World War I, Cyclops was commissioned 1 May 1917, Lieutenant Commander G. W. Worley in command. She joined a convoy for St. Nazaire, France, in June 1917, returning to the east coast in July. Except for a voyage to Halifax, Nova Scotia, she served along the east coast until 9 January 1918 when she was assigned to Naval Overseas Transportation Service. She then sailed to Brazilian waters to fuel British ships in the South Atlantic, receiving the thanks of the State Department and Commander-in-Chief, Pacific. She put to sea from Rio de Janeiro 16 February 1918 and after touching at Barbados on 3 and 4 March, was never heard from again. Her loss without a trace is one of the sea's unsolved mysteries.