40 ships were attacked by German submarines in waters off Florida in WWII. The accompanying map only includes ships that were attacked or sunk as a result of hostile military action. Some discrepancies exist between reference sources as to the cause of several sinkings. There may have been additional ships torpedoed, whose sinkings were undetermined.
Of the ships listed, the tanker J.A. Moffet, Jr. did not actually sink; however, after being towed into port it was declared a total loss. The freighter William Cullen Bryant was towed to dry dock in Tampa and repaired. The tankers Delisle and Pennsylvania Sun were damaged but not sunk. The Eclipse, the Java Arrow and the La Paz all sank in shallow water and were later raised and repaired. These ships are indicated on the map with an asterisk.
Several small vessels were reported sunk by German submarines and were not included on the main list due to their relatively small size: the lighter (barge) Worden, which was sunk by U-109 while firing torpedoes at the La Paz on May 1, 1942 off Cape Canaveral; the small British vessel E.P. Therlault, attacked in the Straits of Florida by U-753 on May 22, 1942; the trawler Gertrude, sunk by U-166 in the Straits of Florida on July 16, 1942; and the lighter (barge) AMC-67, which was attacked off Jacksonville by U-96 in August 1942.
The U.S. Navy airship (blimp) K-74 was shot down by U-134 after it attacked the surfaced submarine off the Florida Keys on July 18, 1943. This was the only case where an American blimp was shot down by hostile action during the war.
The commander of U-84 reported hitting an unidentified tanker with torpedoes during his attack on the freighter William Cullen Bryant, southwest of Key West on July 21, 1942.
At least three merchant ships (Edward S. Luckenback, Bostiljka, Gunvor) and the destroyer USS Sturtevant sank, apparently after accidentally hitting U.S. Navy mines that were placed north of Key West to deter German submarines from operating in the area.
The tanker Gulfland, sank off the southeast coast after colliding with another ship at night while under blackout conditions due to the German submarine threat. The freighter Benwood appears to have suffered a similar fate off the Florida Keys.
Although several German U-boats were attacked by U.S. forces off Florida, only one was confirmed sunk. In this action, the U.S. Coast Guard vessel Thetis dropped depth charges to sink the German submarine U-157 southwest of Key West.
Main reference sources: Shipwrecks of Florida by Steven D. Singer and Axis Submarine Successes 1939-1945 by Jurgen Rohwer.