USS R - 12 ( SS - 89 ) USS " R - 12 " ( SS - 89 ) was an " R " - class coastal and harbor defense submarine of the United States Navy . Construction . Her keel was laid down by the Fore River Shipbuilding Company of Quincy , Massachusetts on 28 March 1918 . She was launched on 15 August 1919 sponsored by Miss Helen Mack , and commissioned at Boston , Massachusetts on 23 September 1919 with Lieutenant F . J . Cunneen in command . History . " R - 12 " remained at Boston , Massachusetts until she headed down the coast on 11 March to New London , Connecticut , whence she operated until the end of May . She then continued south to Panama ; transited the Panama Canal at the end of June ; arrived at San Pedro , California , in July ; and with the hull classification symbol " SS - 89 " , departed the California coast for Pearl Harbor at the end of August . Arriving on 6 September 1920 , she remained in Hawaiian waters , with occasional exercises on the West Coast and off Johnston Island until 12 December 1930 . On that date , " R - 12 " got underway for the East Coast and returned to New London , Connecticut on 9 February 1931 . She conducted exercises with Destroyer Squadrons of the Scouting Force into the spring , then following overhaul trained personnel assigned to the Submarine School . On 27 September 1932 , she departed New London for Philadelphia , Pennsylvania , where , after decommissioning on 7 December , she joined other " R " - boats berthed there in the Reserve Fleet . Some seven and a half years later , on 1 July 1940 , " R - 12 " recommissioned in ordinary and shifted to New London to complete activation . Recommissioned in full on 16 October , she sailed for Panama on 10 December , arrived on 23 December , and into October 1941 , patrolled the approaches to the Panama Canal . On 31 October , she returned to New London and for the next three months operated off the New England coast . In February 1942 , she commenced patrols to the south and for the next year operated primarily from Guantanamo Bay and Key West , Florida . In March and April 1943 , she was back at New London , then in May she returned to Key West , Florida , where she trained submarine rs for the remainder of her career . Accident and loss . Shortly after noon on 12 June 1943 , " R - 12 " , while underway to conduct a torpedo practice approach , sounded her last diving alarm . As she completed preparations to dive , the forward battery compartment began to flood . The collision alarm was sounded and a report was made that the forward battery compartment was flooding . Orders were given to blow main ballast , but the sea was faster . In about 15 seconds , " R - 12 " was lost . The commanding officer , one other officer , and three enlisted men were swept from the bridge as the boat sank and were rescued . Forty - two lives were lost . " R - 12 " was stricken from the Naval Vessel Register on 6 July . Discovery . Sometime before 25 May 2011 , an exploration team led by Tim Taylor aboard the expedition vessel " RV Tiburon " located and documented the wreck of the World War II submarine USS " R - 12 " . The reason for her loss remains unknown . In making the discovery , the team deployed a state of the art autonomous underwater robot which collected first ever imagery of the remains of " R - 12 " . They are collaborating and sharing their findings with the US Navy . RV Tiburon intends to launch an future expedition to further investigate the possible causes of the sinking , and collect detailed archeological baseline data . References . 3 . Loss of R - 12 , CDR John Alden USN Ret . , THE SUBMARINE REVIEW , JULY 2008 , PAGE 107 - 119 .