Lenton was promoted to sub-lieutenant by the end of that year and he was a lieutenant aboard the light cruiser HMS Mauritius in 1944.
That same year he volunteered for service in the Royal Indian Navy and was commanding the auxiliary patrol vessel Oostkapelle in 1945.
Lenton joined the journal Shipbuilding and Shipping Record in 1960 and began writing books and articles.
Lenton published his famous "Construction Tables" which were widely sought after each month.
His life's work led to his magnum opus British and Empire Warships of the Second World War (1998), published by Greenhill Books, which followed on from a series of books on the American, German and Royal Navies of World War II.