From: Dictionary of American Naval Fighting Ships, Vol. IV p 261

Marysville

Cities in California, Kansas and Michigan ; towns in Ohio, Pennsylvania and Washington.

Marysville originally PC--857, was redesignated PCE (R)--857, 19 June 1943 ; laid down by Pullman Standard Car Manufacturing Co., Chicago, Ill., 21 December 1943 ; launched 4 May 1944 ; and commissioned at New Orleans, La., 26 April 1945, Lt. Comdr. Robert K. Thurman in command.

After shakedown along the coast of Florida, PCE ® ) -- 857 steamed to the Canal Zone 31 July for duty in the Pacific. She transited the canal 2 August, reached Pearl Harbor the 19th, and on the 29th began escort duty under ComServRon 2. Following the Japanese surrender, she operated out of Pearl Harbor among the islands of the central Pacific. Thence in 1946 she returned to the west coast and underwent conversion to an underwater sound laboratory ship at Long Beach, During her 6-month conversion, all armament was removed and laboratory spaces, transducer columns, and a 5-ton capacity boom were installed. She reclassified E--PCER--857 on 22 March 1947 and began duty in support of the Pacific Projects Division of the Operational Test and Evaluation Force, conducting underwater sound experiments off the coasts of California and Mexico until July 1949.

On 5 July 1949 she departed San Diego for a 2-month cruise, during which she shot underwater photographs, to a depth of 730 fathoms, off Alaska and among the Aleutians. Spending the next 10 months in operations off southern California. she readied for a "Mid Pac" expedition sponsored jointly by the Naval Electronics Laboratory and the Scripps Oceanographic Institute. From 29 July until 1 November she conducted experiments near Kwajalein, Bikini, and Johnston Islands with the Institute's MV Horizon. Upon her return to San Diego she commenced 10 years of operations along the shores of the eastern Pacific, concentrating on the southern California and Central American coasts to San Salvador. Named Marysville 15 February 1950, she received a thermistor chain for use in charting ocean currents and layers by temperature gradients that year. The 19-ton self-contained chain hoist, with a greater thermal reading speed than the previously used bathythermograph, was capable of recording thermoclines over a larger area in a shorter time thus enabling the ship to study more accurately the theory that the oceans, like the atmosphere, contain warm and cold fronts which divert underwater sound. Marysville, with her new equipment, resumed operations along the west coast, from Puget Sound to the tip of Baja California, In January 1963 marine biological experiments were added to the vessels studies of internal wave motions and construction of three-dimensional plots of isothermal layers.

Three years later, in 1906, Marysville extended her operational range. Departing San Diego 17 January she headed south on a 3-month cruise to study the Cromwell and Humboldt currents in the vicinity of the Galapagos Islands and the coast of Ecuador. Returning 23 April, she got underway again 22 June for a 4-month study of thermal conditions in the Japanese Sea, concentrating on the Kuroshiro and Oyashiro currents. This latter cruise was the vessels first venture across the Pacific to join the 7th Fleet since her commissioning. Since returning to San Diego 4 November 1966 Marysville has continued into 1969 her oceanographic investigations of ocean temperatures and underwater sound along the west coast.