Key West's Hidden WWII Submarine Base, Sonar School, and the Truman Annex

Fun Fact Friday: Key West's Hidden WWII Submarine Base, Sonar School, and the Truman Annex Host Michele O'Connor introduces a "Fun Fact Friday" episode focused on Historic Marker #57 near the Outer Mole and the US Coast Guard Cutter Ingham Museum area, explaining how today's calm Truman Annex was once a major WWII submarine hub. She describes the site's evolution from the 1845 Fort Zachary Taylor Army installation to Navy control, the construction of five metal finger docks for submarines, and Key West's wartime role countering German U-boats that sank thousands of ships, including nearly 50 off Florida in 1942. Key West submarines escorted supply convoys and helped support the Pacific War, while the Fleet Sonar School relocated there in 1940, training thousands in sonar. The base was designated in 1946, became obsolete with nuclear submarines, and was decommissioned in 1974, later transforming into today's parks, amphitheater, cruise-ship pier, and tourist area. 00:00 Welcome to Fun in Key West 01:26 Episode teaser WWII waters 02:50 Fun Fact Friday kickoff 03:51 Marker 57 location today 05:17 Base origins and docks 07:12 U-boats off Florida 08:42 Key West wartime missions 10:08 Sonar school revolution 11:22 Decommission to Truman Annex 13:09 Questions and reflections 14:29 Live comments and travel tips 17:25 Final recap and subscribe