SAN DIEGO -- A professional surfer who was drunk when he crashed his speeding car in Del Mar last year, killing his 24-year-old passenger, was sentenced Wednesday to four years in state prison.

Milton Willis, 53, pleaded guilty on June 18 to gross vehicular manslaughter while intoxicated and an allegation that his actions on June 6, 2008, caused great bodily injury to Bradley Dillahunty of Laguna Niguel.

Vista Judge Daniel Goldstein could have sentenced Willis to a maximum 10 years in prison.

Willis was critically injured in the 1:40 a.m. crash at Coast Boulevard and 20th Street and had to be hospitalized.

Authorities said Willis, who had borrowed Dillahunty's car, lost control of the Toyota Avalon while driving about 65 mph in a 25-mph zone. The sedan hit a parked car and smashed into a palm tree.

Sheriff's officials said evidence at the scene -- including a strong odor of alcohol -- suggested that drinking was a "major" causative factor in the wreck.

Just prior to the accident, Dillahunty, who worked as a musician, had been at Jimmy O's, a sports bar-restaurant on West 15th in Del Mar, sheriff's Sgt. Randy Webb said at the time. It was not clear where Willis had been in the hours leading up to the accident.

Willis, who ran a North County surf school with his identical twin, Michael, is famed for plying some of the world's largest waves and credited as a developer of "tow-in surfing," in which a surfer is pulled onto a very large breaker by a cord attached to a personal watercraft or helicopter.

The Willis brothers also established the first surfing class in a U.S. public high school in 1972 and co-authored a book of philosophical essays inspired by their surfing careers.