When World War II broke out, he was technically still a foreigner and not allowed to serve in the theatres of war, despite being by that time an officer in the Royal Navy. But when Greece entered the war on the Allied side, he was able to serve in the Mediterranean theatre, which he did with great distinction. He was credited with saving the lives of his shipmates on the occasion that German dive-bombers damaged the ship HMS Wallace—of which he was the second in command—in a night-time attack. He proposed launching a makeshift raft equipped with smoke floats, which in the darkness had the desired effect of fooling the German bombers into thinking that that itself was the damaged destroyer.