Joan Irvine Smith’s Former Husband Presumed Dead : Disappearance: Russell Sylvanus Penniman III, 62, was last seen swimming near his West Indies beach home. Authorities believe he suffered a heart attack.

Russell Sylvanus Penniman III, a former Newport Beach businessman known as an adventurer, aviator and yachtsman, is presumed dead after disappearing two weeks ago while swimming at the beach in front of his home in the West Indies. He was 62.

The ex-husband of Irvine Ranch heir Joan Irvine Smith, Penniman vanished on June 13 while swimming at sunset near his home in St. Vincent on tiny Mustique Island, west of Barbados. An air and sea search was called off after four days, and although his body has not been found, authorities speculate that he suffered a heart attack.

Penniman is survived by his wife, the former Lorie Blanton, of Mustique Island; sons, Lt. Cmdr. Russell Penniman IV of San Diego, a Navy pilot; and Bruce Penniman of Virginia; daughter, Elizabeth Penniman Schmidt of Virginia; brother, John Griscom Penniman of New York; sister, Anne Penniman Ferguson of La Jolla, and three grandchildren, Russell Penniman V, Elizabeth Irvine Huntley Penniman and Caroline Meriwether Schmidt. He was Smith’s second husband, married to her for several years in the mid-’50s.

Penniman, a retired Navy captain who had flown attack planes off carriers, also was an avid hunter and fisherman. He was a member of the Newport Harbor Yacht Club, the Newport Beach Tennis Club and the Rancheros Visitadores.

From the late 1960s until he retired about five years ago, he headed Penniman and Associates, a Newport Beach land sales company that sold large tracts to developers.

Penniman, born in Los Angeles and raised in Laguna Beach and Winchester, Mass., had lived for the past few years on a three-acre property on the tiny, 3 1/2-by-1-mile island of Mustique, an enclave of the rich and famous.

“He lived full time there but was still a member of the Newport Harbor Yacht Club and spent a lot of time here. He was just here last month on the Rancheros ride,” said Madeline Swinden, his sister-in-law.

Penniman, who had a heart condition, was a strong swimmer, scuba diver and former lifeguard, so family members speculate that he suffered a massive heart attack while swimming in the bay outside his home. U.S. Navy fliers helped in the search, but they could not find his body, which probably was pushed into a nearby channel by strong currents.

Penniman began flying airplanes when he was 16, and his honeymoon with Smith was a yearlong flight with stops in South America. In the late 1950s he was involved in delivering surplus aircraft to revolution-prone South American countries but stopped that work after his first delivery when a top general in Peru was seriously wounded in a duel with the minister of war over the funding of the airplanes.

“He was truly dedicated to his profession of flying,” said Athalie Clarke, Smith’s mother. “They had quite a ceremony when they relieved him of his command when he retired.”

A private service for family and friends is scheduled for Thursday. Family friends said he requested a celebration of life instead of a memorial service when he died.