Georgia Clark Sadler, a Navy captain who became the U.S. Naval Academy’s first female instructor, died Nov. 30 of complications from Alzheimer’s disease at Inova Alexandria Hospital. The Alexandria, Virginia, resident was 81.

Mrs. Sadler was the first woman to hold numerous positions in the Navy. She opened the door for future generations of women in the military throughout her career and in retirement.

She graduated first in her class at Women Officers School in Newport, Rhode Island, and was commissioned as an ensign in the Navy in 1963. Mrs. Sadler taught political science at the Naval Academy in 1972 after completing her junior assignments in Washington, D.C., and Hawaii, graduating from intelligence school and earning a master’s degree. She became the first female intelligence briefer for the chairman of the Joint Chiefs of Staff in 1975, which was one of her proudest career accomplishments, her husband said.

“The only command post women would have been eligible for in those days would have been cleaning command and other administrative duties,” said Dudley Sadler, her husband and a retired Navy reserve captain. “She had a highly restrictive future ahead of her, but she followed a nontraditional career path. She had this international experience because of having been in Beirut, Lebanon, and traveled a lot in Europe on vacation.”

“That’s why she chose the intelligence school. It seemed like that would give her more opportunity, and it did,” he added.

Born in Los Angeles, Mrs. Sadler was the daughter of Thomas E. Clark, who worked for the Arabian American Oil Company, and Anne Pipa, a homemaker. Mr. Clark’s job brought the family to Dhahran, Saudi Arabia, in 1954, and Mrs. Sadler attended high school at American Community School in Beirut. Her family evacuated with other Americans from Lebanon during Sadler’s senior year because of a political crisis.

Mrs. Sadler attended Drury College in Springfield, Missouri, graduating with a bachelor of arts in education and physical education in May 1962. She joined the Navy for better teaching opportunities, Mr. Sadler said, after struggling to find a teaching job in Phoenix, where her family had moved.

She met her husband of 47 years at Defense Intelligence School in Washington, D.C., where she was the only woman in a class of 80 men. Mrs. Sadler worked for the Defense Intelligence Agency throughout her career. She had expertise in Southeast Asia and assisted with Philippines base negotiations.

In 1970, she was selected for a graduate program at the University of Washington in Seattle, where she studied public administration. At the time, the Navy was recruiting more women to higher positions and decided to hire women as faculty members at the Naval Academy.

“There was resistance and a lot of harrumphing on the part of men, but ... the beat went on,” her husband said.

Midshipmen in Ms. Sadler’s class did not stand up when she entered the room the first day of instruction, as midshipmen traditionally do for commanders, Mr. Sadler said. She believed the gaffe was caused by the summer uniform that she wore not displaying her rank clearly.

“She handled that in typical Georgia fashion and didn’t get upset or anything. Just turned and looked at the guys and said, ‘OK, well, I’m going to do this again. I’m going to go out the door and come back in. And you’ll talk it over, and you’ll know what to do,’ ” Mr. Sadler said.

As a leader, Mrs. Sadler was known as confident and levelheaded. “She didn’t chew people out. She’d look you square in the eye and say, ‘I’m going to do this again,’ ” her husband said.

Two years after women started serving aboard ships, she was selected to lead the women’s program section for the Chief of Naval Operations. She was heavily involved in placing women on ships, a new development that was met with resistance from male officers. Mrs. Sadler started writing journal articles advocating for women in the Navy. That advocacy continued throughout her retirement.

After she acted as the head of the Defense Intelligence Agency’s Soviet and Warsaw Pact division, she was promoted to captain in 1984. She served overseas in the Philippines the next year, according to the Naval History and Heritage Command.

She retired in 1991 after 29 years. She became the director of the Women in the Military Project at the Women’s Research and Education Institute, a think tank in Washington, writing many journals and book chapters about women’s equality. The Australian Army invited her in 2001 to present a paper on the history of American women in the military. Sadler was also on the first board of directors for the Military Women’s Memorial at Arlington National Cemetery.

In her free time, Sadler was a passionate woodworker. She traveled to Franklin, Indiana, every year to attend the Marc Adams School of WoodWorking. Some of her pieces are on display at Goodwin House Alexandria.

In addition to her husband, she is survived by her niece, Lori Gibson, of Nashville, Tennessee. She is preceded in death by her sister, Carol Gibson.

Ms. Sadler’s memorial service will be Jan. 28 at 3 p.m. at Goodwin House Alexandria, at 4800 Fillmore Ave. in Alexandria, Virginia.