紀伊水道
After shakedown training along the New England seaboard from Portsmouth, New Hampshire, and New London, Connecticut, "Gar" departed New London 24 November and transited the Panama Canal on 3 December 1941 en route to San Diego, California, where she arrived three days after the attack on Pearl Harbor. She prepared for combat in the Mare Island Naval Shipyard, then departed San Francisco, California, on 15 January 1942 for Pearl Harbor. Her maiden patrol, from 2 February to 28 March, was conducted around Nagoya and the Kii Channel entrance to the Inland Sea of Japan. She torpedoed and sank the 1520-ton cargo ship "Chichiubu Maru" on 13 March.