(Updates with end of competition and winners)
By Laila Kearney
SAN FRANCISCO, Jan 24 (Reuters) - A 40-year-old wave rider from South Africa claimed his second Mavericks International surfing championship on Friday, as he led two dozen competitors carving into crests up to five stories tall in the northern California's famed surf contest.
Grant "Twiggy" Baker, who hails from Durban and clinched his first Mavericks victory in 2006, was awarded a $12,000 grand prize at the end of the daylong competition, which draws tens of thousands of fans each year to the sleepy coastal town of Half Moon Bay, 30 miles (48 km) south of San Francisco.
"Twiggy's timing, when he's paddling into big waves, is probably better than anyone else I've seen. He has a knack for putting himself as deep as possible and still making it," fellow contestant Mark Healey said in a statement posted on the Mavericks website.
The year's race, which organizers had considered postponing due to fierce winds earlier in the week, featured waves between 40 and 50 feet (12-15 meters) high, breaking a half-mile off Pillar Point Harbor, a contest spokesman said.
Skies were slightly overcast and winds were ideally low the day of the competition, spokesman Gary Bayless said from Mavericks Surf Shop, the competition headquarters.
Stormy weather has led to monster waves in California and Hawaii and caused treacherous conditions that forced the cancellation of a separate surf competition in the Aloha State.
Two-dozen professional surfers hand-picked by organizer Jeff Clark compete in the California event, which launched in 1999. Surfing started at 8 a.m. local time and wrapped up at about sunset.
Shane Dorian, 41, from Hawaii, placed second to claim $6,000 in prize money, followed by Californian Ryan Augenstein, 31, who will receive $5,000 for finishing third. The other contestants will receive $1,000 each.
Spectators of the monster swells have been barred from the beach and surrounding towering cliffs since the 2010 contest, when the roaring waves injured multiple onlookers.
"The giant waves of Maverick's generate surges that leave the small beach at Maverick's underwater, with no beach to stand on," the website says.
Event-goers now gather outside on the grounds of the Oceano Hotel and Spa in nearby Princeton Harbor, where the competition is streamed live on giant screens. Last year, some 30,000 people watched from the hotel parking lot, Bayless said.
A surf event in Hawaii set for Wednesday was canceled when organizers deemed conditions too stormy to produce the quality of waves needed, despite Oahu seeing its largest surf swell in a decade.
"We got waves of 50 to 60 feet (15-18 meters)on Wednesday, but it was very stormy and adverse conditions," said Jodi Wilmott, organizer of the Quiksilver in Memory of Eddie Aikau big wave invitational. "There were high wind warnings. Coming onshore (the wind) absolutely shreds and destroys the waves. It's not the clean and organized swells you can ride.
The event is on standby as organizers monitor upcoming swells to the islands through the end of February, which is the deadline for the event.
"It's been a very active winter sweep season so we are optimistic that other opportunities will arise by then," Wilmott said. (Additional reporting by Malia Mattoch in Honolulu; Writing by Steve Gorman; Editing by Dan Whitcomb, Andrew Hay and Ken Wills)