In the early days of WWII, the British Royal Navy based the main part of the Grand fleet at Scapa Flow, in the Orkney Islands north of Scotland. Protected as it was by blocking ships and underwater cables, the anchorage considered impregnable to submarine attack.
The harbor at Scapa flow had been home to the British deep water fleet since 1904, a time when the place truly was, all but impregnable. By 1939, anti-aircraft weaponry was all but obsolete, old block ships were disintegrating, and anti-submarine nets were inadequate to the needs of the new war.
The men of the German Unterseeboot U-47 commanded by officer Günther Prien, were not impressed. U-47 entered the Royal Navy base in the evening hours of the October 13, 1939. By 12:55am on the the 14th, they were within 3,500 yards of the unmistakable silhouette of the WWI era Revenge Class Battleship, HMS Royal Oak.
Believing he had a certain kill, Prien aimed two of his four torpedoes at the Battleship, and the other two at the 6,900 ton Pegasus, which he’d mistaken in the dark for the much larger HMS Repulse. Tubes one, two and three fired successfully, torpedoes away, but #4 jammed. Only one found its mark, blowing a hole in the starboard bow of the Royal Oak, near the anchor chains.
On the battleship, Captain William Benn was told the most likely cause was an internal explosion, either that or a high flying German aircraft had dropped a bomb. Damage control teams were assembled to assess the damage, while aboard U-47, Prien thought his one hit had been against Repulse (Pegasus). He was prepared to run, but saw no threat from oncoming surface vessels. Coming about and firing the stern torpedo, the crew worked to free the jammed #4 torpedo tube, while reloading bow tubes 1-3. That one missed as well, and the Germans cursed their luck.
The electric torpedoes of the era were highly unreliable, and this wasn’t shaping up to be their night.
Finally, tubes one and two were reloaded, and the jammed tube #4 was serviced and ready to go. U-47 crept closer and, at 1:25am, fired all three torpedoes at the Royal Oak. All three found their target within ten seconds of one other, blasting three holes amidships on the starboard side. The explosions set off a series of fires and ignited a cordite magazine and exploding with a fiery orange blast that went right through the decks.\
Royal Oak rolled over and sank in thirteen minutes. 833 sailors and officers were lost from ship’s company of 1,234, including Rear Admiral Henry Evelyn Blagrove, commander of the 2nd Battle Squadron.
The Royal Navy considered the anchorage so secure that, even now, searchlights and anti-aircraft fire raked the sky, searching for the air attack that wasn’t there. Captain Benn was almost alone in believing that his ship was attacked by torpedo. The cause of the sinking was still being argued over the next day, when divers went down and found a German torpedo propeller. Only then was it understood that the Kriegsmarine had taken the war, into British home waters.
The successful attack at Scapa Flow was a crushing defeat for the British, and payback for the Germans. The entire German High Seas Fleet had been interned there at the end of WWI. Admiral Ludwig von Reuter wasn’t about to let his fleet fall into allied hands, and ordered the lot of them, scuttled. British guard ships succeeded in beaching a few at the time, but 52 of 74 vessels had sunk to the bottom.
Many of those wrecks were salvaged in the interwar years, and towed away for scrap. Those which remain are popular sites for recreational divers, but not Royal Oak. As a designated war grave, Royal Oak is protected by the Military Remains Act of 1986. Unauthorized divers are strictly, prohibited.
The wreck of the Royal Oak lies nearly upside down in 100′ of water, her hull just 16-feet beneath the surface. Each year, divers place the red St. George’s Cross with the Union Flag of the White Ensign at her stern, a solemn tribute to the honored dead of World War 2, and to the first Royal Navy battleship lost in the most destructive war in history.