Lionel Whittam joined the Royal Navy Volunteer Reserve, London Division as Probationary Midshipman, RNVR on 24 May 1939. On 13 October 1939 he was appointed to the battlecruiser HMS HOOD. This was followed by an appointment to HMS SHELDON on 18 October 1940. He was promoted to Acting Sub Lieutenant, RNVR on 22 May 1941 and appointed to the Escort Vessel HMS MILFORD on 22 May 1942 and then to HMS VARBEL on 25 September 1942 where he trained for service in X-Craft. He was further promoted to Lieutenant, RNVR on 1 July 1943.

Having completed his X-Craft Training he was selected for the operational crew in HMS X7 for the attack on the German battleship

TIRPITZ in Kaa Fjord, Northern Norway on 22 September 1943. X7 with a passage crew on board was towed to the operational area by HMS STUBBORN (Lieutenant Arthur Anthony Duff RN). The operational crew took over from the passage crew for the approach to the target and the attack. X7’s two side cargoes were placed under the TIRPITZ. Still in the area at the time of the explosion, X7 was damaged and became impossible to control.

X7 was then surfaced alongside a gunnery target and the Commanding Officer, Lieutenant Place stepped onto it but X-7 went back to the bottom with three of the operational crew still onboard. One of them, Sub Lieutenant Aitken, managed to escape sometime later and was rescued by the Germans. He and Lieutenant Place became Prisoners of War but Lionel Whittam and William Whitley were lost. The attack was successful in that the TIRPITZ was badly damaged although not sunk.

Lionel Whittam was posthumously Mentioned in Dispatches (see London Gazette of 1 August 1944) “for great daring and enterprise in the attack the German Battleship Tirpitz carried out by Midget Submarines in September 1943“.  He is buried in the Tromso Cemetery in Norway in Grave D 8 and is commemorated on the 12th Submarine Flotilla Memorials at Rothesay on the Isle of Bute and at Kylesku.