In 1964, recognizing his uncompromising patriotism, his devotion to work, and his more than thirty years of service as a Navy artist, Beau was granted their most prestigious civilian award, the Navy Meritorious Public Service Citation.
Beau wrote to the Secretary of the Navy, the Honorable Paul H. Nitze, thanking him. "Please accept my sincere and heartfelt thanks for this great honor, which I treasure above all other commendations. The work accomplished over the years in painting and recording for history the activities of the Navy I love so well, I feel has been a great privilege and a distinct pleasure."
In 1964 he also began painting a series of Revolutionary War sailing ships which occupied him for the next ten years. It is some of his best work, reminiscent of the first ship portraits he executed in the early 1930s. Like his contemporary, British artist Montague Dawson, Beaumont depicted traditional maritime subjects including the USS Constellation and the USS Constitution. The Navy used these Revolutionary War images as part of the publicity for the National Bicentennial Celebration.
Beau continued his work for the Navy until the end of his life. In 1966, he traveled to Vietnam to record the Navy's small craft operations against the Viet Cong, but his active participation with the Navy slowed considerably, after visiting Vietnam. In subsequent years, he and Dot traveled extensively, visiting Navy friends and other acquaintances throughout the world. Beau never did retire. A backlog of commissions kept him painting five days a week. On the stairwell of their Laguna Hills home, a woven mat from an English pub with the words "Take Courage", gave Beau the inspiration to climb the stairs every day to his studio to paint, well into his eighties.
Beau also executed a commission to paint twenty-four ship portraits for the National Steel Company between 1970 and 1973. And in 1976 Beau was honored with a retrospective exhibition at the Laguna Beach Museum of Art, just two years before he passed away. The show contained 127 works chronicling the years 1931 to 1976. It was very well received. An excerpt from the museum brochure reads "Today, as we honor this Artist Laureate of the Fleet, Mr. Beaumont continues to research with acute perception and produce with unwavering quality historically significant commissions."
On January 23, 1978, Beau passed away, survived by his wife, four children, thirteen grandchildren, and eight great-grandchildren.
Learning of Beau's death, his good friend, Admiral Arleigh Burke, wrote to Dot: "Great talent is given to but few men, and Beau gained the respect and admiration of his peers by his great paintings. But he also gained even more ardent admiration from those of us who were not expert in his difficult field, but who, as sailors realized that Beau put the spirit of the sea into his paintings as it is felt and cannot be expressed by those who go down to the sea in ships. Beau loved the sea and his work showed it. He loved the Navy as few men do, and Navy people in generations to come will be grateful to him for his inspiring paintings....He was beloved for his personal characteristics... He was a man of great integrity coupled with unusual understanding. He was a great man. He will be sorely missed."