On the afternoon of December 19, 1917, south of the Lizard in Cornwall, as the daylight was fading, Stephen Gronow, the Captain of the Vinovia, spotted the powerful beam from Wolf Rock Lighthouse with some relief. The Vinovia, a ten-year-old Cunard cargo-liner ship, was heading back to London from New York with an enormous cargo of brass and copper for use in the war munitions industry. Gronow, former Chief Officer of the Cunard passenger liner the Aquitania, belonged to the Royal Naval Reserve. Many of his fellow Cunard officers, when war came in 1914, joined Allied warships or undertook naval duties on hurriedly converted merchant vessels. In March 1917, he transferred to become Master of the steam-driven Vinovia, running vital supplies from North America to British ports.
Since North America was vital to the Allies’ war effort, the German Navy was determined to cut off these vital supply lines and targeted the merchant vessels mercilessly. In November 1917 alone, 64 Allied merchant vessels were sunk due to enemy action. German submarines patrolled the coastal waters, tracking and picking off Allied merchant ships carrying supplies, troops and, as in the case of the Lusitania, civilian passengers.