Richard Lennihan, M.D., of Wilmington, Del., and Vineyard Haven, died peacefully at the age of 86 on June 12. Martha’s Vineyard, where he spent summers sailing as a child, was like a second home to Dr. Lennihan. He raced for Vineyard Haven Yacht Club as a boy, first crewing for Alden Besse. As a teenager he raced in his own boat, The Irish Gal, one of the first Vineyard Haven 15s designed by master boatbuilder Erford Burt.

Dr. Lennihan continued to vacation on the Vineyard throughout his life. He loved sailing, birding at Felix Neck Wildlife Sanctuary and picnicking at Tashmoo while the sun set over the ocean. Mostly he loved opening his home to friends and sharing in their enjoyment of the Island. His last trip, just two weeks before his death, included visits with the Rev. Alden Besse and Jim Norton of Bayes Norton Farm, his friends since the 1930s.

Dr. Russ Hoxsie, beloved family physician on the Island, was a classmate of Dr. Lennihan’s at Cornell Medical School. Dr. Lennihan was responsible for bringing Dr. Hoxsie to the Island and arranging for him to take over the practice of the previous general practitioner. By a remarkable coincidence, Charlie Parton — owner of Alley’s General Store in West Tisbury — was another 1952 Cornell Medical School graduate. Dr. Charles Parton was Dr. Lennihan’s roommate and closest friend in medical school.

Dr. Lennihan was predeceased by his sisters Pat (Patricia Wulsin) of Cambridge, and Babs (Burke Honey) of Paremata, New Zealand, who were also avid sailors at Vineyard Haven Yacht Club in the 1930s and 1940s. Their family owned Holmes Hole, the dry goods and toy store on Main street in Vineyard Haven in the 1950s and 1960s. The family home on West Chop was built in the late 1700s by Captain Holmes, for whom Holmes Hole (Vineyard Haven Harbor) was named.

Dr. Lennihan was the first physician in Delaware to practice vascular (blood vessel) surgery and most recently was a major advocate for his hospital’s pioneering Center for Heart and Vascular Health. He and his wife Marge moved to Delaware from the Boston area in 1962, raising five children and creating a backyard nature-lover’s paradise at the house they shared for 50 years.

Dr. Lennihan was not only a skilled and meticulous surgeon, he was also an old-time doctor, making house calls, delivering medications to shut-ins, taking plenty of time explaining things to his patients, and especially providing emotional support for his patients before and after surgery. He was known as a great teacher for the younger doctors at the hospital, eager to pass along his knowledge of surgery, which was his great passion. He also took the foreign doctors under his wing, acting like a father to those who were far from home.

On a trip to East Africa, Dr. Lennihan visited an orphanage which he “adopted,” sending financial support for many years to the young Eritrean boys who referred to him as “father.” To his great satisfaction, some of these boys went on to medical school and are now practicing as doctors in countries around the world.

He began running marathons in 1976, completing many Marine Corps and Boston Marathons. He also participated in shorter races, including the Delaware Senior Olympics at which he set five age-group records for 80 and older.

An avid birdwatcher, Dr. Lennihan built birdhouses for his backyard and went on birdwatching vacations to places like the Galapagos Islands. His love of nature took him all over the world on adventures with his wife, including trips to Bhutan, the Amazon River and Outer Mongolia. His photographs captured these varied landscapes as well as his beloved family and his wife’s lush meadow garden.

Dr. Lennihan had a special gift for making friends wherever he went. He was much loved, not only by his patients and by the generations of physicians whom he taught, but also by the people he met in every walk of life.

Born in Boston, Dr. Lennihan joined the Navy in 1944, subsequently graduating from Harvard in 1948. The following year he married his classmate Marjory Reynolds. After graduating from Cornell Medical School, he did his internship at the University of Virginia Hospital, then his surgical residency at Boston City Hospital.

Beyond all his professional and athletic accomplishments, Dr. Lennihan was perhaps proudest of his five children and their contributions through their varied careers: Marion Begabati Lennihan of Cambridge, author and homeopath; Laura Lennihan Kerrich of Chappaqua, N.Y., neurologist; Mark Howard Lennihan of Brooklyn, N.Y., photographer and photo editor for Associated Press; Lisa Lennihan of Chicago, Ill., psychoanalyst; and Holly Lennihan Cox of Alexandria, Va., architect. He is survived by his wife, his children and his eight grandchildren, who were his greatest joy. The eldest is now in medical school, following in her grandfather’s illustrious footsteps.

Dr. Lennihan will be remembered for his enthusiasm, optimism and generosity. Through his own work and that of the doctors he taught and supported, he touched the lives of people around the world. Donations in his memory may be sent to Felix Neck Wildlife Sanctuary, P.O. Box 494, Vineyard Haven, MA 02568.