Mr. Kumana, shown here in 2007, was credited with helping to save the lives of future President John F. Kennedy and other PT-109 crew members during World War II. (MCC Shawn P. Eklund/US Navy via AP)

Eroni Kumana, a Solomon Islander who was credited with helping to save the lives of then-Navy Lt. John F. Kennedy and his PT-109 crew members after their boat was destroyed by a Japanese warship during World War II, died Aug. 2.

He was 93, according to an announcement by the John F. Kennedy Presidential Library and Museum in Boston. Other details about the death of Mr. Kumana, who lived on the island of Ranongga in the Solomons’ western province, were not immediately available.

Seventy-one years ago, during the early morning hours of Aug. 2, 1943, the future President Kennedy was the skipper of a patrol torpedo boat cruising the waters of the Blackett Strait, along the route of the so-called Tokyo Express supply convoy, when his craft was struck by a Japanese destroyer.

Two U.S. crew members died in the collision. Eleven others — including Kennedy and a mate he would tow to safety by holding the man’s life-jacket strap in his mouth — swam for hours before finding refuge on Plum Pudding Island. Their ordeal would last for nearly a week.

Despite his exhaustion and injured back, Kennedy ventured into the waters again in a vain search for Allied vessels that might be able to rescue his stranded crew. Suffering from thirst and hunger, he and his men later swam to the larger Olasana island, where they hoped to sustain themselves with coconuts.

Then-Lt. John F. Kennedy is shown here in 1942 aboard PT-109. (Handout/Reuters)

Meanwhile, an Australian coast watcher had sent local scouts to look for survivors from PT-109. Many native islanders harbored deep enmity toward the Japanese and assisted the Allies by acting as guides, supporting rescue efforts and monitoring enemy movement.

Mr. Kumana and another scout, Biuku Gasa, first spotted Kennedy and another U.S. serviceman on Aug. 5 on Naru Island, where the two Americans had gone in search of food, water and aid. The islanders mistook Kennedy and his fellow sailor for Japanese and fled.

“We ran to the canoe,” Mr. Kumana said in an oral history cited by National Geographic, “and paddled to Olasana.” There, they found the remaining members of Kennedy’s crew.

“Some of them cried, and some of them came and shook our hands,” Mr. Kumana recalled. Kennedy arrived later and embraced the natives, Gasa said.

With few tools to record a message, Kennedy was delighted when Gasa suggested that he carve a note in a coconut. Mr. Kumana picked one from a tree.

NAURO ISL . . . COMMANDER . . . NATIVE KNOWS POS’IT . . . HE CAN PILOT . . . 11 ALIVE . . . NEED SMALL BOAT . . . KENNEDY, read the skipper’s message.

Mr. Kumana and Gasa made a nearly 40-mile journey by canoe to an Allied outpost and delivered Kennedy’s carved message. The two scouts then assisted in the rescue mission that brought the crew to safety on Aug. 8.

“I was young, but I wasn’t scared,” Mr. Kumana said, according to National Geographic.

Kennedy kept his engraved coconut and used it in the Oval Office as a paperweight. He had invited the two islanders to his inauguration, according to accounts, but they were unable to make the trip.

Mr. Kumana had hoped to see Kennedy again and was devastated to learn of his assassination in 1963. “My sadness was great,” Mr. Kumana said. “I would never meet him” again.

In later years, Mr. Kumana largely faded into obscurity. In 2002, a National Geographic crew searching for the wreckage of PT-109 found Mr. Kumana. Traveling with the crew was Max Kennedy, a son of President Kennedy’s brother Robert. The president’s nephew said that he spoke to Mr. Kumana through the translation of the islander’s son — who was named John F. Kennedy.

Mr. Kumana “had absolutely risked his life and risked a horribly painful death by paddling through these islands,” Max Kennedy said in an interview with The Washington Post. “It’s an extraordinary thing for a young man to do that. . . . My whole life growing up I had heard about these two men who saved Uncle Jack.”

In 2007, representatives of the U.S. Navy honored Mr. Kumana for what he had done. “This is an individual who has had a very significant role in the history of our nation and the world,” Navy Secretary Donald Winter said at the time. “It was an honor to meet the man who rescued the future 35th American president.”

Gasa, the other islander, is reported to have died in 2005.

To honor Kennedy, Mr. Kumana presented a prized piece of shell to the former president’s family. The gift was placed on the Kennedy grave site at Arlington National Cemetery and is now part of the museum in Boston.

Mr. Kumana also built a stone monument to the president, whom he considered an honorary chief, at his island home.

“The chiefship of Kennedy will remain here, even after I die,” Mr. Kumana said during the National Geographic expedition, “strong as ever, as hard as this rock.”