Crew of a British X -Class midget submarine, part of the British Pacific Submarine Fleet, at his action station

How The Royal Navy Helped Make D-Day Possible

Bowfin Museum

The 52 foot midget submarines, although tiny, were built to sink the most powerful German combatants, but ended up paving the way for British forces.

Advanced X-Class (X-20 and X-23) took up station off of Sword and Juno beaches five days before June 5th, 1944, D-Day’s original execution date. Once on station, they dropped to the sea floor waiting for the signal that the invasion would come the next day. They occasionally surfaced for a quick periscope recon and to listen to the 10pm BBC news broadcast for a coded message. By 4am on the morning of June 6th, crews knew the invasion was underway. Landcraft were able to navigate to Sword beach using the light beacons from the midget submarines. The X-Crafts literally lighting the way.