USAS American Mariner The USAS " American Mariner " was a U . S . Army research vessel from January 1959 to 30 September 1963 . She was originally assigned to DAMP Project by the Advanced Research Projects Agency ( ARPA ) to attempt to collect radar signature data on incoming intercontinental ballistic missiles in the Caribbean , the South Atlantic Ocean , and the Indian Ocean . Her initial operations involved providing radar track on the Atlas missile , which was under development at the time . Subsequently , she provided track on other types of missiles as they proceeded through their development and operational stages . Laid down in 1941 as the Liberty ship SS " George Calvert " ( MC # 20 ) , she first saw service as the U . S . Coast Guard training ship TS " American Mariner , where she served until 1953 when she was placed in reserve . After her Army career , she was transferred to the U . S . Air Force on 1 October 1963 , and was redesignated the USAFS " American Mariner . After Air Force service , she was transferred to the U . S . Navy and designated the USNS " American Mariner " ( T - AGM - 12 ) . In 1966 she was scuttled in shallow waters of the Chesapeake Bay about 5 NM north west of Ewell , Smith Island , MD to be used for a target ship . She appears to have been the only ship to have served in the U . S . Coast Guard , the U . S . Army , the U . S . Air Force and the U . S . Navy after being built for service with the United States Merchant Marine . History . Initial construction and early history . The keel for SS " George Calvert " ' ( build number 2007 / MC Hull 20 ) was laid on 15 August 1941 in the Bethlehem - Fairfield Shipyard , Baltimore , Maryland . She was launched 30 December 1941 , sponsored by Miss Margaret E . Voss . At 65 . 4 % complete , she was transferred for conversion to a training vessel . She had additional superstructure added to accommodate more personnel and was renamed the TS " American Mariner " . The conversion was completed 10 March 1943 and she was delivered to the War Shipping Administration – Division of Training . She then served the U . S . Coast Guard as a cadet training ship , together with the SS " American Seaman " and the SS " American Sailor " . After this service to the U . S . Coast Guard she was placed in a standby status on the Hudson River as she was no longer needed for the war effort . In 1950 she was transferred to the US Merchant Marine Academy in Kings Point , New York for use as a training ship . She was returned to the Hudson River reserve fleet on 9 December 1953 . Conversion to Missile Tracking Ship . On 18 June 1958 she was removed from the Hudson River , and transferred to the U . S . Army . and outfitted in early 1959 with state - of - the - art C - band - frequency narrow - beam radar tracking equipment for the Army . The ship , redesignated USAS " American Mariner " , was then assigned to Mathiesen Tankers Industry , which provided the crew for the ship , and to RCA Service Company , which provided the necessary radar equipment and technical personnel , and Barnes Engineering Company , which provided the necessary optical equipment and technical personnel for the ship ' s new DAMP Project assignment . Atlantic Missile Test operations . During her years on the DAMP Project the USAS " American Mariner " operated various types of long - distance , narrow - beam radars to gather data on intercontinental ballistic missiles . This period ( 1959 – 1963 ) represented the infancy of the " space race " and ballistic missiles in particular , and it was necessary , for security reasons , for the U . S . to determine if missiles could be identified in space ( from a radar signature , for example ) before they re - entered the atmosphere . Hopefully , for it was not known at the time , various types of missiles would provide different radar signatures . This would be important for identifying American missiles from those of other countries . This , if such data could be provided and fed into the computers of that era , would lead to the development of American anti - ballistic - missile defense systems , such as Nike - Zeus , which was a part of Project Nike . During her Atlantic Ocean operations , the USAS " American Mariner " gathered radar signature data of ballistic missiles launched by the Cape Canaveral Air Force Station into the Broad Ocean Area located off of the coast of Florida , as well as intercontinental ballistic missiles launched into the South Atlantic Ocean near Ascension Island . Collection of signature data of each missile type was important during the in - flight portion of the missile . This was especially true during the missile re - entry as the missile descended through the atmosphere to its designated target point in the ocean , which is where the USAS " American Mariner " was usually positioned with its narrow - beam radars activated and searching in order to " lock on " to the missile . Tracking of missiles during re - entry was often difficult since , at times , the missile contained decoy pods which would be ejected during re - entry to deceive tracking personnel at the target test location . As a result , it was difficult to ensure that the vessel ' s radars were tracking the actual vehicle and not one of the decoys . The decoys were intended to deceive the " enemy " and not necessarily the test vessel ' s radars ; however , those who designed the decoys needed to know how effective they actually were . All such data was very important at this critical time in early space and missile development during the early years of the " Cold War . " Pacific Missile Test operations . In the Pacific Ocean in 1962 , the " American Mariner " gathered radar signature data of missiles launched during Operation Dominic atmospheric nuclear testing . The ship operated in the Johnston Island area and , during one major test , the nuclear event exploded in the upper atmosphere directly over the vessel in order to determine if the radars on the USAS " American Mariner " could track and identify missiles in the nuclear cloud . While investigating reports of foreign missile testing in the North Pacific Ocean in November 1962 , the USAS " American Mariner " became caught up in Typhoon Karen , which caused significant rolling , and some flooding , of the top heavy ship , which was quickly repaired . After completing test operations in the Pacific Ocean , the USAS " American Mariner " returned to the Eastern Test Range in the Atlantic Ocean , by transiting the Panama Canal in January 1963 . Support of NASA . While in the Pacific Ocean , the USAS " American Mariner " was temporarily assigned in late September 1962 to NASA in support of NASA ' s Project Mercury . During Wally Schirra ' s MA - 8 transits over the Pacific Ocean , the USAS " American Mariner " successfully provided radar track of the capsule . While assigned to this mission , all data provided by the ship was transmitted by unclassified methods in accordance with NASA mission principles . Vessel Support . While performing her missile - tracking operations , the " American Mariner " was reprovisioned in various ports in both the Atlantic and Pacific Oceans : In the Atlantic Ocean , shore - side support was generally provided at San Juan , Puerto Rico ; Antigua Island ; Chagaramus , Trinidad ; Recife , Brazil ; Monrovia , Liberia ; Dakar , Senegal ; and Cape Town , South Africa . During Pacific Ocean operations , support , including logistics , mail , embarkation and transfer of technical personnel , occurred at Pearl Harbor , in Hawaii , at Midway Island , and at Johnston Island . Vessel and equipment overhaul . Since the " American Mariner " remained at sea for approximately four years under U . S . Army service , the ship regularly required shipyard service on her hull and her electronic equipment . Extensive shipyard overhauls and drydocking were conducted in Brooklyn , New York ; Baltimore , Maryland ; San Juan , Puerto Rico ; Long Beach , California ; Pearl Harbor , Hawaii and Dakar in Senegal , Africa . Extensive technical enhancements in equipment [ L - band and UHF - band radar dish installation ] were conducted in Cape Town , South Africa with the assistance of local technical personnel . Prior to participating in nuclear testing operations during the Spring and Fall of 1962 under Operation Dominic , the USAS " American Mariner " was outfitted at Pearl Harbor , Hawaii , with protective anti - radiation equipment , including emergency warning lights and a water spraying system that , when turned on during an atomic event , would cover the ship with a fine spray of water intended to remove and wash away nuclear contamination . Retirement . The operations of the " American Mariner " , a radar - signature data gathering ship , was replaced , in mid - 1964 , by two U . S . Air Force ships , the " H . H . Arnold " and the " H . S . Vandenberg " , both Advanced Research Instrumentation Ships ( ARIS ) which gathered and provided metric data to the Air Force . Fate . In October 1966 , she was scuttled in shallow water with demolition charges by Navy Underwater Demolition Team # 22 . Settling upright in 20 feet of water , she appears to be merely anchored there . The hulk was used for target practice by naval aviators flying out of NAS Patuxent River until at least 1971 . Her hulk is still visible in the Chesapeake Bay , at , roughly midway between Point Lookout and Smith Island .