Tom Morey, whose creation of the small, flexible, lightweight Boogie Board introduced millions to the exquisite sensation of riding waves on their bellies instead of having to balance themselves upright atop bigger, heavier surfboards, died on Oct. 14 in a hospital in Laguna Hills, Calif. He was 86.

His son Sol said the cause was complications of a stroke.

“Tom Morey’s invention allowed more people to experience wave riding than any person in the history of surfing,” Jim Kempton, president of the California Surfing Museum in Oceanside, said in a phone interview. “It didn’t create radical surfing performances, but it was a really fun and simply way for people to understand wave riding.”

By the time he created the Boogie Board, Mr. Morey had become an expert surfer, an engineer at Douglas Aircraft, a surf shop owner, a surfboard builder, the creator of interchangeable surfboard fins and the co-creator of a three-piece surfboard that could fold up into a suitcase.

In July 1971, while tinkering in his backyard on the main island of Hawaii, he cut a piece of polyethylene foam in half with an electric knife and shaped a rounded nose and square tail with the heat of an iron. (He used pages from The Honolulu Advertiser to seal the board during the ironing, and images from the newspaper remained.)

To test this 4½-foot long, 3-pound board, he took it to the west side of the island, paddled out on the water and then experienced the waves in a way he had never felt while standing or kneeling on a surfboard.

“I could actually feel the wave through the board,” he said in an interview on the surf museum’s website. “On a surfboard, you’re not feeling the nuance of the wave, but with my creation I could feel everything. I was thinking, ‘It turns, it’s durable, it can be made cheaply, it’s lightweight, it’s sage.’”

He added, “God, this could be a really big thing.”

He initially named it S.N.A.K.E. for all the body parts (side, navel, arm, knee, elbow) that touch the board when someone lies on it. But he settled on “boogie,” for the “wiggle and jiggle” that he associated with swing music.

Mr. Morey began producing Boogie Boards in 1974, took on a partner, Germain Faivre, and opened a factory in Carlsbad, Calif. Demand surged. In 1977, the company sold 80,000 Boogie Boards, according to Mr. Morey’s website. Some reports at the time suggested that the sales had helped spark a marked increase in surfing in Southern California and that Boogie Boarding had, at least temporarily, become as popular as skateboarding.

“The movements you can put on the board are unlimited,” Debby McMahon, a 17-year-old surfer, told The Press-Tribune of Roseville, Calif., in 1977, “just like the boogieing on the dance floor.”

But Mr. Morey did not get rich from the Boogie Board. He sold his company sometime in 1977 or 1978 to Kransco, a toy manufacturer, for an undetermined moderate sum and received no royalties.

Mr. Morey was philosophical about his lost windfall.

“Say I had sold this for a billion dollars,” he told The Los Angeles Times in 2003. “l’m still going to be sitting here in my bathing suit. I’m not going to eat any more than I’m eating.”

Thomas Hugh Morey was born on Aug. 15, 1935, in Detroit, to Howard and Grace Morey. His father was a real estate agent, his mother a homemaker. A family move to Laguna Beach, Calif., when Tom was young introduced him to the Pacific Ocean and surfboarding.

Enrolling at the University of Southern California, he started as a music major but earned his bachelor’s degree in mathematics in 1957. While still in college, he and a classmate, Bob Tierney, created the Fantopper, a shapeable, honeycomb paper hat. They sold 100,000 of them (some to Joan Collins and Red Skelton), and the hat was featured in a cover story in Parade magazine that posed the question, “Will paper hats become a fad?”

Mr. Morey joined Douglas Aircraft in the late 1950s after a stint in the Army. At Douglas he specialized in composite materials (which he already knew about from his early surfboard making) but left several years later to open a surf shop and build custom surfboards in Ventura, Calif. He organized the Tom Morey Invitational surfing tournament in Ventura in 1965; it’s believed to be the sport’s first prize-money competition.

After the sale of his Boogie Board business, Mr. Morey continued to work on surfboard innovations while playing drums with a band at the Mauna Kea Beach Hotel on Hawaii’s big island. In 1985, needing money, he moved to Washington State, where he took a job with Boeing and returned to working with composite materials.

He moved back to Southern California in 1992 and resumed making surfboards, including the durable, pillowy Swizzle, whose core was made of polypropylene foam, the material inside car bumpers. The Swizzle had some success for a decade.

“I’m embarrassed it took me 20 years to think of it,” Mr. Morey told The Los Angeles Times in 2000, by which time he was making surfboards under the one-letter name Y. “It was, like, ‘Duh.’”

He continued to surf into his 70s.

In addition to his son Sol, Mr. Morey is survived by his wife, Marchia (Nichols) Morey; three other sons, Moon, Sky and Matteson; a daughter, Melinda Morey; five grandchildren; and three great-grandchildren. A daughter, Michelle, died in 2003. Mr. Morey’s marriage to Jolly Givens ended in divorce.

Mr. Morey worked on various nonsurfing inventions, including a football that produced a better spiral, a three-player chess game, a sailboat with an adjustable mast and a type of hovercraft. He also sketched out plans for a water park called Morey Boogie Land. None of the projects were commercialized.

“Almost everything has not been invented yet,” Mr. Morey told Sports Illustrated in 1982. “Some people think of one or two new things in their lifetime. I have the misfortune of being a fabulous inventor.”