In the years after World War II, Beau's Navy work continued at a rapid pace. In late 1945, he took three cruises on the USS Iowa, the USS Los Angeles, and the USS Midway, sketching and painting Naval activity. In 1946, he was designated as the Official Artist for "Operation crossroads" the Bikini Atoll atomic bomb tests in the South Pacific, conducted by the US Navy. He witnessed the two blasts from the Able and Baker bombs as an observer on board the flagship, USS Fall River. At one point, he was sitting on a buoy completing his sketches of the wreckage of the USS Arkansas. So close was he to the demolished ship, that he had been exposed to a high level of radioactivity "I was ordered to dispose of all my garments and have a thorough scrubbing down!", to counter the affects of the overdose of radiation. Luckily the scrubbing down was successful and he did not contract radiation sickness. In all, Beau made 180 on-the-spot sketches and 16 paintings, including two watercolors showing the now famous mushroom clouds and one painting of the sinking of the famed aircraft carrier, USS Saratoga. The paintings highlighted the Beaumont exhibitions at the National Gallery of Art, Washington, D.C. and the Museum of the Science and Industry in Chicago, Illinois.
The years 1947 to 1957 mark a more relaxed pace in Beau's career. A cruise on the USS St. Paul to Japan and China in 1947 greatly influenced his subject matter. "Here was an artist's paradise," he remarked of Peiping. At that time of Chinese civil war, he watched demonstrations in the Forbidden City, where the Chinese marchers shouted "Down with Stalin, Down with Russia!" The influence of the Asian watercolor style stayed with Beau forever. Some of his most poignant works come from this period, including images of The Temple of Heaven and Calm on the Yangtse.
Early in the 1950s, Beau incurred two major injuries to his right arm which slowed his usual pace and kept him away from war correspondence work in Korea. Instead, he busied himself with teaching, which he loved. Out of necessity, he learned to paint with his left hand, allowing him to continue work on the ever-present commissions from Naval officers and others who wanted ship portraits. He completed two murals in the early 1950s, one for the Jonathan Club in Los Angeles and one for the law firm of Spray, Gould & Bowers, also in Los Angeles.