Larry Stevenson, a California lifeguard who helped popularize skateboarding in the early 1960s by marketing his Makaha boards to riders eager to essentially surf on land, died March 25 at a medical facility in Santa Monica, Calif. He was 81.

Mr. Stevenson had Parkinson’s disease, said his son, Curt Stevenson.

“He was the guy who said, ‘I can merge surfing with the skateboard culture,’ ” said Michael Brooke, author of the 1999 skateboarding history “The Concrete Wave.” “At one point in time, there was nobody bigger making skateboards.”

From his lifeguard tower at Venice Beach, Mr. Stevenson noticed kids riding rickety, often-homemade, skateboards. He knew he could engineer a better skateboard and, as publisher of Surf Guide, used the magazine to link the wheeled pastime to the exploding surf scene.

Working with his wife, the former Helen Payne, in their garage, he began building skateboards designed to resemble surfboards. He improved the ride by replacing the steel wheels with a clay version and upgraded the trucks, the device that holds the wheels.

By 1963, he had begun mass-producing skateboards. That year, he also made the first professional skateboard, naming it after legendary surfer Phil Edwards.

The same year, Makaha sponsored the first skateboard contest, with about 100 competitors at Pier Avenue Junior High in Hermosa Beach, Calif. His company also was the first to sponsor a skateboard exhibition team, according to skateboarding histories.

He promoted the brand with Surf Guide ads that showcased such famous surfers as Mike Hynson and Mike Doyle riding Makaha skateboards.

Around town, Surf Guide employees passed out free boards and recruited a crew of “young innovators who put down the first roots of sidewalk surfing’s stylistic aesthetic,” Keith David Hamm wrote in the skateboarding history “Scarred for Life” (2004).

Makaha — named for a big-wave Hawaiian surf spot — emerged as an industry leader and by the end of 1965, had sold $4 million in skateboards.

In 1965, the American Medical Association labeled skateboards “a new medical menace.” Safety experts urged stores not to sell skateboards and advised parents not to buy them.

The fad died as quickly as it began, as did sales for Makaha.

“One week I was getting so many orders, people were leaving them on my doorstep. . . . The next, I was getting 75,000 cancellations in a single day!” Mr. Stevenson recalled in “The Skateboarder’s Bible” (1976).

He shut down the factory in 1966 and returned to his lifeguard chair, but he continued to ponder building a better skateboard.

In 1969, Mr. Stevenson applied for and was later granted a patent for a design that would help revolutionize skateboarding — the kicktail. His was a metal bar that sloped up and away from the board, which allowed riders to tilt the plank and made it easier to do tricks.

Mr. Stevenson began mass-producing a molded kicktail skateboard “that looked hot enough to rejuvenate the sagging skateboard market,” Mike Purpus, a Makaha skateboard team member, wrote in 2005 in the South Bay Easy Reader.

With Mr. Stevenson’s invention, the first generation of skateboarders laid down the foundation of tricks and style, according to skateboarding histories.

Other manufacturers soon began copying Mr. Stevenson’s design and almost universally refused to pay him royalties. Financially, the invention nearly ruined him as he tried to protect the patent in court. In 1982, the U.S. Supreme Court refused to review a decision that found the kicktail too “simple” to merit patent protection.

With the advent of the kicktail and the polyurethane wheel, which made the ride faster and smoother, skateboarding fully took off again in 1973. Makaha rode the second wave, and Mr. Stevenson recouped his losses from the earlier skate bust. His son now heads the company, which is known for its retro line of skateboards.

Richard Lawrence Stevenson was born Dec. 22, 1930, in Los Angeles. He served as an airplane mechanic in the Navy during the Korean War and then received a bachelor’s degree in business from the University of Southern California. From 1963 to 1965, he published Surf Guide, and in 1988, he became a publisher of the skateboarding magazine Poweredge Magazine.

At Makaha, Mr. Stevenson remained active late in life, making modern high-performance skateboards and reproductions of vintage designs.

His marriage ended in divorce. Survivors include his son.

— Los Angeles Times