The Second Battle of Heligoland Bight was a naval engagement in World War I. On 17 November 1917, German minesweepers clearing a path through the British minefield in the Heligoland Bight near the coast of Germany were intercepted by two British cruisers, HMS Calypso and HMS Caledon, performing counter-minesweeping duties. The German ships fled south toward the protection of the battleships SMS Kaiser and SMS Kaiserin, commanded by Rear Admiral Ludwig von Reuter. The two cruisers engaged the German battleships, while their own screening force of the battlecruisers HMS Tiger, HMS Renown, HMS Repulse, HMS Courageous, and HMS Glorious of the First Battlecruiser Squadron, commanded by Admiral Sir Charles Napier, were coming up to assist.
All personnel on the bridge of HMS Calypso, including her captain, were killed by a 12-inch shell. HMS Repulse, Captain William Boyle, briefly engaged the German battleships, but the Germans made it back to the safety of their own minefields with the loss of only a torpedo boat.