When war broke out William was helping to produce Short Stirling heavy bombers. The factory was bombed so he joined the Home Guard and later, aged eighteen, he was enlisted in the Royal Marines in May 1942. He trained at HMS Wildfire, a ‘Stone Frigate’ or Naval base on land. He was then assigned to HM Fort Knock John in the Thames Estuary, armed with 3.7-inch AA and Bofors guns. He recounts how officers ‘fished’ using hand grenades.

He then trained on Landing Craft, Flak (LCF) in preparation for the invasion of France. They sailed on LCF 36 to support the landings on D-Day but they were unaware it was the invasion until they left. His task was to man one of the many light anti-aircraft guns on board. They helped the troops ashore by blowing away a German sniper that was hiding in a church steeple.

After the Normandy landings they were assigned to support the assault on Walcheren Island, in the Scheldt estuary to help open the port of Antwerp. During the attack his LCF was hit by German fire but did not sink. Later they took wounded men off the flotilla leader which was sinking and took the survivors to the Belgian coast. Due to bad weather there was little air support and therefore enemy resistance was stronger. He finished the war on HMS Robertson, near Sandwich but they were not needed and helped local farmers. He recalls being frightened in action but the feeling usually passed.