Stanley Lewis received a letter from the National Service Board (Armed Forces) dated 16th June 1941: 

"Mr. S.C. Lewis of 14 Dale Road, Newport must submit himself to medical examination by a medical board at 10.15 am on Monday 23rd June 1941 at the Medical Board Centre, St. Mark's Institute, Queen's Hill, Newport, Mon."

Lewis made a drawing of the event.

Having been deemed fit by the Army, Lewis left Newport to report for duty with a large incomplete canvas folded into his luggage. Throughout the war, he made a habit of capturing moments from his service career in sketches.

Lewis’ Attack on the Battleship Tirpitz by the Fleet Air Arm depicts Operation Mascot, an assault on the Kriegsmarine vessel whilst she was moored for repairs in Kaafjord, Norway. Painted at the end of the war, this image can now be seen at the Fleet Air Arm Museum at Yeovilton in Dorset.

Recalled Lewis, “Sir Arthur ‘Bomber’ Harris visited the camp to see progress on the work. I couldn’t believe it was him. Anyway, he decided to sit on a stool close by, and lifted his coat tails to sit down, but my palette and paints were on it! I just managed to whip it away in time, or he’d have sat on the lot and got paint all over his arse. Never mind the sinking of the Tirpitz, I’d have been sunk if that had happened. All the Top Brass on the camp were in such a high state of alert because he was here, and all he wanted to do was talk to me about Spanish Painting; Murillo, Velásquez and his favourite, Goya. I remember thinking - here is a man who sent hundreds of young airmen to their deaths last night, and all he wants to talk about is Art and Painters!”