Category: U-Boat Panic

• The Great Wall of Florida

  The Great Wall of Florida was the rumor that the United States was secretly building a submerged barrier, gate system, or engineered underwater wall across or near the approaches to the Gulf in order to trap German U-boats before they could penetrate southern waters. In the strongest form, the structure was imagined as a hidden anti-submarine wall stretching through strategic Florida and Gulf passages, supported by nets, explosives, sensors, or controlled channels. The historical context made the rumor plausible enough to survive: anti-submarine patrols and coastal defense concern were real before and during World War II, and German U-boats genuinely operated off Florida and in the Gulf of Mexico. The conspiracy version transformed distributed defense into a single invisible maritime barrier.