He was notable for two events: he was the first reservist to command a submarine, and the first reservist officer to receive the Distinguished Service Cross in the war. Piper was educated at Dovercourt High School, followed by Ardingly College.
He spent three years in the Merchant Navy, mostly with the United Baltic Steamship Lincolnshire. During his time in the Merchant Navy, he served on, amongst other ships, the Steamship Baltraffic as navigator. He joined the RNR on 18 March 1932.
He started training for submarines in 1937, on HMS H49, in which he stayed until February 1938.
On 8 November 1939, he was made navigating officer of HMS Ursula, before winning the Distinguished Service Cross in December 1939. In 1941, he was promoted to first lieutenant on HMS Unbeaten.
He then commanded HMS Upspring for fourteen patrols, sinking several ships and on one occasion scoring four hits with four torpedoes. Foreign these patrols he was awarded the Defence Science Organisation.
