Today I Found Out's video: The British Almost-Kamikazes of World War II

The Japanese weren't the only ones with this little idea. In Their Finest Hour, the second volume of his memoir The Second World War, Winston Churchill wrote: “The only thing that ever really frightened me during the war was the U-boat peril.” From the moment war was declared, the German Navy or Kriegsmarine waged a campaign of unrestricted submarine warfare against British and Allied shipping in the Atlantic. Being a small island nation, Britain was dependent on foreign imports for nearly 70% of its food, and the campaign was intended to starve the British into submission and bring them to the negotiating table. The ensuing naval struggle, known as the Battle of the Atlantic, would be the single longest continuous campaign of the Second World War. At the start of the war, the Royal Navy was ill-equipped to deal with the U-boat menace, having relatively few destroyers and aircraft carriers with which to escort and protect merchant shipping. Weapons and tac-tics were also largely inadequate, with most U-boats being able to dive and slip away long before any at-tack could be brought to bear. Furthermore, the limited range of Allied aircraft resulted in a vast 600-kilometre wide area south of Greenland known as the “Mid-Atlantic Gap” or the “Black Gap” over which air cover could not be provided. To get around these limitations, the Admiralty resurrected the WWI-era convoy system, gathering merchant ships into groups of around 30-70 before shepherding them across the Atlantic. While at first glance this practice might seem like it would just create a juicier target for the U-boats, there was method to the madness. In the pre-convoy system, when each ship had to plot its own independent course across the Atlantic, the chances of a given U-boat randomly stumbling upon a ship were relatively high. In the vastness of the Atlantic ocean, however, even a convoy of 70 ships presented a target not much larger than a single ship, making them harder to find. Plus, grouping ships together made it much easier for a small number of escort vessels to protect the convoy. The system proved sur-prisingly effective, with less than 30% of the some 2,700 Allied ships sunk by U-boats during the war being torpedoed while in convoy. Yet despite this, the situation for the British was about to become even worse...