About 40 of John Rieder's relatives, including many of his children and grandchildren, stood and cheered as he received a black graduation cap and was formally instructed by Principal William Fortgang to shift his orange tassel from left to right.
"It's the thrill of a lifetime," Rieder, 84, said afterward.
His two older brothers already had enlisted in 1943 when the 16-year-old left his Queens high school for Rome, N.Y. He worked as a mechanic at the Rome Air Depot until his 17th birthday. He enlisted a few weeks later.
After boot camp, he joined the crew of the USS Bogue. The escort aircraft carrier was deployed in 1945 to the Aleutian Islands, but by the time it arrived, the Japanese had surrendered.
"They found out I was coming," Rieder kidded.
The honorary diploma was the idea of his 34-year-old grandson, also named John, who wrote the high school, his alma mater, to request the honor. The diploma was presented during a brief ceremony before the start of Tuesday night's school board meeting.
Rieder thought he was there to celebrate the accomplishments of a granddaughter, Nadine Robinson, who will be a junior at East Rockaway Junior-Senior High School next fall.
Family members -- he had nine children, 13 grandchildren and nine great-grandchildren -- said Rieder has always been modest about his own achievements, including his military service.
They said he returned to Queens at age 19 after two years in the Navy. He met a young woman named Eileen Falk at a Woolworth's in Flushing -- they were married 57 years when she died in 2007 -- and wound up becoming a manager there.
He later built a career in the appraisal business, retiring at 65.
Theresa Rieder, 59, of Valley Stream, said her father deserves the diploma for everything he taught his children.
"He has taught us the importance of patriotism and of family and love," she said. "Each and every one of us knows how to fold the American flag, how to handle the American flag, the respect of country, of family and of each other."
After the ceremony, the family celebrated at a nearby American Legion post, where Rieder had served as a commander.
Rieder said he completed his high school studies in Manhattan after the war. He walked away before getting a diploma, but never regretted it.
"I didn't need it," he said, looking at an appreciative family. "Look what I got."