Depends on the sources i guess
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.[2] 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, two other officers, and three enlisted men were swept from the bridge as the boat sank and were rescued. Forty-two lives were lost.[1] R-12 was stricken from the Naval Vessel Register on 6 July.