USS Sturgeon (SS-187), a , was the second ship of the United States Navy to be named for the sturgeon. Its 1944 sinking of the Japanese troopship , killing more than 5,000 Japanese, was one of the highest death tolls from the sinking of a single ship in history, and its 1942 sinking of the prisoner ship was the worst maritime disaster in Australian history. Construction Her keel was laid down on 27 October 1936, by the Mare Island Navy Yard. She was launched on 15 March 1938, sponsored by Mrs. Alice N. Freeman, wife of Charles S. Freeman, Commander, Submarine Force, United States Fleet at the time. The boat was commissioned on 25 June 1938. 1938–1941 Sturgeon completed builder's trials in Monterey Bay and began her shakedown cruise on 15 October, visiting ports in Mexico, Honduras, Panama, Peru, Ecuador, and Costa Rica before returning to San Diego, on 12 December 1938. She was assigned to Submarine Squadron (SubRon) 6 and operated along the West Coast as far north as Washington. She made two squadron cruises to Hawaii with the Pacific Fleet: from 1 July to 16 August 1939 and from 1 April to 12 July 1940. The submarine departed San Diego on 5 November 1940 for Pearl Harbor and operated from there until November 1941. Sturgeon stood out of Pearl Harbor on 10 November, headed for the Philippine Islands, and arrived at Manila Bay on 22 November. She was then attached to SubRon 2, Submarine Division (SubDiv) 22, United States Asiatic Fleet. First patrol: December 1941 Sturgeon was moored in Mariveles Naval Section Base on 7 December 1941 during the Japanese attack on Pearl Harbor. She put to sea the next afternoon to patrol an area between the Pescadores Islands and Formosa. A small tanker was sighted the afternoon of 9 December, but it remained out of torpedo range. The submarine found a convoy of five merchant ships accompanied by a cruiser and several destroyers on 18 December. As she came to periscope depth within attack range of the cruiser, she was sighted by one of the escorts approximately away. She started going deep but had only reached a depth of when the first depth charge exploded, breaking numerous light bulbs but causing no serious damage. Sturgeon began silent running and evaded the escorts. On the evening of 21 December, the submarine sighted a darkened ship believed to be