A U.S. Navy Nuclear Attack Submarine Sank Due to an ‘Uncovered Manhole’ Mishap

A U.S. Navy Nuclear Attack Submarine Sank Due to an ‘Uncovered Manhole’ Mishap

Key Points and Summary – USS Guitarro sank at the pier in 1969 when an open sonar-dome manhole—left uncovered during transducer work—let floodwater drag the bow under during trimming tests, rapidly cascading into major forward openings. Refloated days later, the “Mare Island Mud Puppy” was repaired, commissioned in 1972, and served two decades across multiple WestPac/Indian Ocean tours before decommissioning in 1992 and recycling in 1994. The Oh…