Thomas Upton “Tom” Sisson Jr., 87, of Rehoboth Beach, Del., and Paris, France, passed away peacefully at his home in Rehoboth Beach, of cancer, on Aug. 31, 2020. He was born Sept. 9, 1932, in San Diego, Calif., to Thomas Upton Sisson and Edith Grey Nance.

As a child during World War II, he followed his mother to various Navy postings on the Atlantic and Pacific coasts, while his father, a career Naval officer, fought in the Atlantic, North Africa and the Pacific.

After graduating in 1950 from St. Albans School in Washington, D.C., where he was chosen senior prefect, Sisson followed his father’s footsteps, entering into the U.S. Naval Academy, in the Class of 1954, graduating in the top 2 percent of more than 800 midshipmen.

Shortly into his 30-year naval career, he sought the adventure and camaraderie of submarines, becoming in 1957 the junior officer on the diesel submarine the Wahoo, where the second-in-command was Bill Crowe, the future chairman of the Joint Chiefs of Staff and later ambassador to Great Britain. That began Sisson’s 15-year career in submarines, broken only by a two-year stint at Stanford University to earn a master’s degree in political science. At 6 feet, 4 inches tall, he always was the tallest man aboard, and another half-inch of height would have barred him from submarines altogether.

With the opening of the submarine nuclear power program, Sisson came into the orbit of the famed and feared Adm. Hyman G. Rickover, excelled in nuclear power school and was assigned to the nuclear attack submarine the Shark as reactor-control officer during its construction. That made Sisson a “plank owner” of the Shark.

It was the first of its kind in the Mediterranean Sea (with Sisson running the nuclear reactor), hosting the Greek royal family and future king of Spain, including a dive. The queen stood on the sail-plane while the Shark, running on the surface, made such a bow-wave that the splash soaked the queen’s legs, leaving her to pad around barefoot aboard for the rest of the several-hour cruise, while her shoes and stockings dried — one of Sisson’s favorite stories. The queen, a great friend of Rickover, was delighted.

Next, Sisson was an engineering officer of the nuclear missile-deterrent submarine the Abraham Lincoln in Scotland when President John F. Kennedy ordered Lincoln to rush to sea on 24 hours’ notice at the height of the Cuban Missile Crisis.

He became executive officer of the nuclear attack submarine the Scamp, where missions resembled the kinds of secret spy missions written in the 1998 book “Blind Man’s Bluff: the Untold Story of American Submarine Espionage” — a book that closed-mouth Sisson and most other members of the “silent service” grumbled ought never to have been written. It was the only way his children learned some of what he had done, more than 30 years after the fact.

Upon earning his master’s, Sisson became commander of the “Blue Crew” shift of the nuclear missile deterrent submarine Ulysses S. Grant. First based in the Pacific, they sailed through the Panama Canal to take up duties in the Atlantic. An exciting moment for his sons was visiting Kennedy Space Center to watch their father test-fire two missiles while the boys rode a nearby destroyer. As an additional treat, that day was the Apollo 15 moon mission “roll-out” of the gigantic Saturn V rocket, which the boys walked around as it slowly crept toward the launch pad.

In 1972, Sisson was assigned to the Pentagon to advise on nuclear weapons policy, including the Strategic Arms Limitation Talks (SALT), and took advanced studies at the National War College. The Secretary of Defense awarded him a 1979 Defense Meritorious Service Medal, stating that Sisson provided “clear, concise answers to major sensitive issues having a direct bearing on national security and policies. Capt. Sisson’s distinctive achievements reflect great credit on himself, the United States Navy and the Office of the Secretary of Defense.”

In 1980, Sisson was posted as U.S. Naval attaché to France, for three years, and liaison to the French Navy for one year, earning a French Order of Merit for diplomatic service.

Sisson retired in 1984 to an apartment in Paris, summering in Rehoboth Beach. He devoted himself first to fly fishing: traveling across the U.S. and Europe, winning a fly-casting trophy in a nationwide competition and giving personal lessons in casting.

Over the decades, Sisson brought his children and grandchildren to France many times, introducing all of them to the wonders of Paris. They will never forget his thoughtfulness in providing long visits in the most beautiful city in the world, led by a man who knew the language, the city, its people, its culture and its cuisine inside-out, like a native, until infirmity brought the trips to an end in about 2018 — a span of almost 40 years.

Sisson later took up ham radio, fitting-out his Rehoboth Beach house with a large hat-like antenna that catches the curious excited eye of every small child on the street, fitting-out the back room as a “radio shack” to communicate all over the world, and joining the local Southern Delaware community of ham radio operators.

Born and raised in the Episcopal Church, Sisson felt a stronger call from the Catholic Church, undertook the necessary studies and was admitted into the Catholic Communion.

Sisson was preceded in death by his beloved first wife, Mary Winslow, in 1999. He is survived by his wife, Mary Mallory Marshall (the former Mrs. Stuart Bowen Sr.); his three sons, Edward, Thomas and Patterson; stepchildren, Stuart Bowen and Sophie Schubert; seven grandchildren; seven step-grandchildren; and great-grandchildren.

A Catholic funeral service and, by coincidence, a birthday celebration, were to be held on Sept. 9, 2020, at Parsell Funeral Homes & Crematorium, Lewes, Del. Interment with military honors will be held at Arlington National Cemetery at a later date. In lieu of flowers, memorial contributions are suggested to St. Albans School; Mount St. Alban; Washington, DC 20016-5069. Condolences may be sent online at www.parsellfuneralhomes.com.