[3] Ramirez de Arellano excelled in sports in the Academy, earning varsity letters in soccer, tennis, and gymnastics.

Upon his graduation, he was commissioned an Ensign and assigned to the USS Ranger, the first ship of the United States Navy to be designed and built from the keel up as an aircraft carrier.

He participated in five war patrols with the Pickerel and led the effort to rescue five Navy pilots and one enlisted gunner off Wake Island.

In May 1946, Ramirez de Arellano was named Commanding Officer of Submarine Base, Saint Thomas, U.S. Virgin Islands.

With the exception of his other two ship commands, the USS Lindenwald (1952–1954) and of the USS Thomaston (1954–1955), Ramirez de Arellano held various administrative and teaching positions — among them Assistant to War Plans Officer, Caribbean Sea Frontier, 10th Naval District (1947–1949) and in the Department of Languages, U.S/ Naval Academy (1949–1952).

He died on May 15, 1980, at Andrews Air Force Base near Washington, D.C. Ramirez de Arellano is described in Rick Riordan's young-adult novel The Blood of Olympus as being a great-great-uncle of the major character Reyna Ramirez-Arellano.

[6] In 2020 Marion Frederic Ramírez de Arellano was posthumously inducted to the Puerto Rico Veterans Hall of Fame.