Kaighn Smith, 92, a prominent Main Line obstetrician/gynecologist, ocean sailing racer, and supporter of women’s rights, died Sept. 18 at his home in Northeast Harbor, Maine.

Dr. Smith’s son, Kaighn Smith Jr., said his father’s health declined after the death of his wife, Ann R. Smith, an Episcopal priest and civil and women’s rights activist, in June. The couple, who were teenage sweethearts, had been married 70 years. Dr. Smith’s condition worsened rapidly after a fall 10 days before his death. His ninth great-grandchild was born four days before he died.

The couple moved full time to their home in Maine from Bryn Mawr in 2012.

Family members and coworkers described Dr. Smith, who was chair of Lankenau Hospital’s obstetrics and gynecology department and director of its residency program for 21 years, as calm, gentlemanly, universally respectful, popular, and highly competent.

“He was one of the last of what we call the giants,” said Andrew Gerson, who is chief of maternal-fetal medicine at Main Line Health, which includes Lankenau. He came to Lankenau to work with Dr. Smith in 1986. Giants, he said, were doctors like Smith who were stars in their field and at their institutions. Gerson said Dr. Smith was a popular teacher who always attracted a crowd of residents and students as he visited patients. “He had a huge experience,” Gerson said. “People just knew Dr. Smith knew what he was talking about.”

Charles Dunton, a gynecologic oncologist who was a resident at Lankenau from 1980 to 1984, said Dr. Smith was an effective teacher who gently led students to the right path without berating them. “He would never make anybody feel that they had done something wrong,” he said. Dr. Smith, he said, was also “one of the best surgeons I ever worked with.”

Dr. Smith made sure that Lankenau (now Lankenau Medical Center) was one of the first hospitals to use fetal monitors during labor. He later supported training doctors who specialized in high-risk pregnancy and gynecologic cancers while some ob/gyns clung to the idea that they could do it all. He brought a nurse midwife into his practice when that was unusual and embraced the training and promotion of female ob/gyns.

Dr. Smith was the son of Katherine Coolidge Smith and Geoffrey Story Smith of Fort Washington. He was the grandson of Edward B. Smith, a founder of the investment firm of Smith Barney & Co.

He attended Chestnut Hill Academy in Philadelphia and then St. Paul’s School in Concord, N.H. He later served on its board of trustees.

After graduating from Harvard University, he went to the University of Pennsylvania School of Medicine. He chose obstetrics after watching a birth. He thought, “That’s for me,” he later told his son. “What could be better than bringing new lives, healthy babies, into the world?”

After his residency, he served in the Navy for two years in Pensacola, Fla. He then worked at the Hospital of the University of Pennsylvania for six years before moving to Lankenau in 1966. He became department chair in 1974, retiring from that position in 1995. He continued to practice until 1999, the year that Lankenau created an endowed chair in obstetrics and gynecology in his name.

Dr. Smith served on the executive committee and board of trustees of Main Line Health from 1992 to 1995. From 1980 to 1981, he was president of the Obstetrical Society of Philadelphia, an organization founded by his great-grandfather Albert Holmes Smith.

He met his future wife in kindergarten. They were a couple in their teens, and she cemented her relationship with the family by actually enjoying a weekend with Dr. Smith and his father on his father’s boat. “He said the secret to marriage was to listen,” their son said. “My mother said the secret to successful marriage is to never go to bed angry.” Both believed a good marriage involved work. As she became more involved in activism, he changed as well. “My dad was quite flexible, and he shifted as she shifted,” he said.

Dr. Smith was also passionate about boat racing. In the late 1950s, he sailed for the Navy in small boats in the Thistle Class.

He later turned to ocean racing, which involved staying on the boat both days and nights and required larger crews. He bought and sailed a Swan 38. Although it had been designed by a respected marine architecture firm, Dr. Smith decided that its keel, a stabilizing finlike structure at the bottom of the boat, was not deep enough. He built a mold for a new one in his basement and then had molten lead from the old keel poured into the mold at a foundry owned by a patient’s husband, his son said.

An avid competitor, Dr. Smith excelled at weighing the many variables that contribute to successful racing. “There’s always a right way,” his son said.

Gertrude “Gay” Smith said her father was always willing to learn new things, like celestial navigation and then GPS. “Not knowing something never stopped him,” she said. “As a child being around that was really amazing. It made me … realize what was possible.”

He went on to sail the Gaylark, named after his three children, to victory in several prestigious races, including the Annapolis to Newport Race, the Marblehead to Halifax race, and the Bermuda race. Dr. Smith was a member of the Cruising Club of America and became its commodore. He was the first commodore to open the club to women, Gay Smith said.

In addition to his son and daughter, Dr. Smith is survived by another daughter, Laurie Parker, as well as four grandchildren and nine great-grandchildren.

A memorial service will be held in summer 2022. Donations in his memory can be made to Planned Parenthood or St. Paul’s School, financial aid.