Under the Water

A large ship in a body of water - Amphibious warfare ship

Lately, we have heard a lot of plans for the Truman Annex property fronted by the Outer Mole Pier harbor. There are a number of plans to turn the land and protected waters into an upscale marina, park, maritime museum, senior housing and any number of other ideas.

The original use of the area started in 1845 as part of the Army installation at Fort Taylor. The base was eventually taken over by the Navy in 1947 and named the “Fort Zachary Taylor Annex to Naval Station Key West.” By 1932, five new metal “finger” docks had been added to the harbor to create a home for Navy submarines.

The submarine docks, dry docks and surrounding support buildings had several specific purposes during World War II. Due to an oversight in the language of the Treaty of Versailles following World War I, Germany was able to amass the largest submarine fleet in the world.

The submarines, or U-boats as they were commonly called, were very successful in inflicting great losses on Allied supply convoys in the Atlantic. During the war 3,000 Allied merchant and military ships were lost to U-boat encounters. While most effective in the mid-Atlantic, where there was a large gap in air power, their threats were felt on the shores of Florida. In May1947, German U-boats sank 47 ships off the shores of Florida. Often, the burning wreckage could be seen from shorelines along the coast.

Submarine missions from Truman Annex included hunting and destroying enemy ships in the Atlantic, Caribbean and Gulf Coast waters. Many missions were to escort ship convoys sailing to and from England with crucial supplies for the European Front. Convoy escorts by Navy submarines and sailors are credited with saving countless lives at sea and abroad during the war.

The base also served to support the Pacific War with the Japanese. New submarines built in east coast shipyards were sent to Key West to receive their crews and orders to sail through the Panama Canal to take their place in the Pacific Ocean Theatre.

The Fleet Sonar School moved to the base in 1940 and was instrumental in training thousands of officers and sailors about newly evolving sonar technology and submarine warfare tactics. The use of sonar on ships was one of the few ways to track the presence or movements of an enemy U-boat.

On March 20, 1946, the Naval Station was designated U.S. Naval Submarine Base Key West. The push for a nuclear-powered submarine fleet made the base obsolete as diesel-powered submarines were retired. The base was closed in 1974 and awaits a new civilian use today.