Larry Stevenson, the former California beach lifeguard whose entrepreneurial vision half a century ago helped create the modern skateboard industry, died Sunday in his room at the Santa Monica-UCLA Medical Center. He was 81.

Stevenson's most significant contribution to skateboarding's early years of equipment innovation was his design of the kicktail, an advancement of control and safety on par with that of the urethane wheel.

According to skate historian Dale Smith, the conceptual design and dimensions of today's modern skate deck essentially mimic Stevenson's patented drawings from the late 1960s. The controlled leverage generated by a skateboard's kicktail has fueled an ongoing trick progression, from simple flatland turns to Torey Pudwill's lipslide to bluntslide combination that helped him win the Tampa Pro on the same afternoon as Stevenson's passing.

Years before the kicktail, however, Stevenson had already rode an increasing wave of skate popularity, starting in 1963 with the formation of Makaha skateboards. As a Venice Beach lifeguard, the young Stevenson had noticed kids riding surf-style along the oceanfront on steel-wheeled skateboards. These rudimentary setups were either homemade rattletraps or equally primitive store-bought models.

Seeing the potential for something better, Stevenson shaped his skateboards like surfboards and marketed them through Surfguide magazine (which he had launched a few months earlier), featuring top surfers Mike Hynson and Mike Doyle sidewalk surfing on clay-wheeled Makaha completes. Within the year, Makaha sponsored skateboarding's first team, held its first demos (called exhibitions back then), and by 1965 was selling upward of 2,000 boards a day. In a few short years, Makaha helped change the public's perception of skateboards from dangerous and annoying toys to functionally and elegantly designed instruments of motion, similar to surfboards.

Regardless, the brand would never recover fully from skateboarding's crash in popularity during the mid- to late 1960s, and Stevenson returned to lifeguarding. His finger, though, never strayed far from the pulse, and during the mid-'80s boom, he launched Poweredge magazine, which had a four-year run and was relaunched in 2009 by Stevenson's son, Curt.

In September, I.E. Distribution (parent company of World Industries) announced a multiyear agreement to produce Makaha skateboards as part of its longboard and cruiser quiver. In 2010, Stevenson was inducted -- along with Stacy Peralta, Craig Stecyk, and Patti McGee -- to the Skateboarding Hall of Fame, which has headquarters at the Skateboard Museum in Simi Valley, Calif.

Curt Stevenson, 46, told ESPN.com that his father struggled with pneumonia and Alzheimer's disease over the past 18 months of his life. "My dad fought so hard over the past year and a half. The doctors wanted to let nature take its course, because he was so frail, but he made a comeback and was out of the hospital for 10 or 12 days. Then we had to rush him back."

Curt added that his father died at 2:30 p.m., listening to his favorite Perry Como CD.