HALF MOON BAY, Calif. — Greg Long has charged down the sheer face of a 40-foot wave, but it has broken with such explosiveness that he is devoured by an avalanche of whitewater.

Embroiled in turbulence and hurtling toward rocks, the San Clemente, Calif., surfer strives for composure and struggles to climb the leash attached to his 9 1/2-foot surfboard, hand over fist.

Mavericks, the infamous big-wave surfing venue beyond Pillar Point, already has killed on this late November morning, which marks the arrival of the season's first large swell.

Overhead, a Coast Guard helicopter crew searches for two fishermen whose boat had capsized.

Long has been submerged in the mid-50-degree water for 20 seconds. He cannot reach the surface. His right eardrum is ruptured, leaving him disoriented. He craves air and tugs so fiercely on his leash that the lower half of his board is pulled under.

Its nose points skyward, eerily, like a tombstone.

These are tumultuous times for expert big-wave surfers. The recession has them on edge; the annual Mavericks contest, one of the world's premier big-wave events, is in jeopardy because of sponsorship troubles. Surfers themselves find it difficult to lure or maintain corporate support.

"Dreams are being crushed," says Hawai'i's Mark Healey, who is sponsored by the surfwear company Quiksilver.

On the bright side, nature pays no attention to economics. A new season has dawned and Aleutian storms are generating massive, swift-moving swells. Surfers will ride them regardless of income.

The swells first slam into Hawai'i, then California, then Todos Santos Island off Ensenada. Surfers, at times, can literally greet the same swell at each location.

On this day at Mavericks, a storm pulse funnels through deep channels and leaps over a crescent-shaped reef, half a mile offshore. Waves here are so dense and thunderous they can register on seismic instruments at UC Berkeley, 30 miles away.

"You can't compare this wave to Hawai'i; it's like nothing else," says Dave Wassell, who lives on O'ahu but has flown overnight with Healey to greet the swell. "It's got cold water. It's got giant sharks. It's got giant waves and giant rocks."

Long is still down. Thirty seconds have passed. A second wave has bounced him off the bottom and propelled him closer to rocks. Again he climbs his elastic leash, like a kid on a gym-class rope.

Long, 25, is a prominent member of the big-wave fraternity, known for taking off deep on the shoulders of the largest waves. After Long won last year's Mavericks contest, Surfing magazine labeled him "one of the top three big-wave riders in the world."

Long lives in San Clemente from March to November. From there he conducts wave-hunting missions along the West Coast, to Hawai'i and occasionally Europe.

From April to May, he is in Mexico. From June to September, he is in South Africa, able to jaunt to Australia and Indonesia.

He is paid by the surfwear company Billabong to maintain visibility in magazines and contests. But he would be riding giants regardless, he said before greeting the new swell, because it is an addiction.

"You get this feeling that is unrivaled by any other feeling," he explained. "I'm sure some people get it in other sports, such as mountaineering and rock climbing. But really, when you're dealing with forces of nature and those forces are moving, the mental and physical challenge is just incredible."

It's the morning of Nov. 29. The mammoth swell has arrived beneath a shroud of fog that prevents surfers from safely venturing on boats or personal watercraft from Pillar Point marina.

They mill about the launch ramp, abuzz with nervous energy.

Grant Washburn, a surfer and filmmaker, recalls the saga of five people who stopped years ago to fish in the impact zone during a long lull, unaware that giant waves broke so far from land.

A set rumbled shoreward and the first wave flipped their boat. Only four surfaced. A second wave swamped them and two surfaced. Ultimately, one fisherman survived.

Only one surfer is known to have perished at Mavericks: Hawai'i's Mark Foo in 1994.