“I was a lifeguard in Southern California,” said Tim Murphy, one of two uniformed state park peace officers who double as lifeguards on the Sonoma County coast. “I never had a rescue where I worried about getting the person back to shore, nevertheless myself. Up here, it really is a mixed bag. You’re in the water sometimes thinking, ‘I hope my backup is here soon, because I’m not sure I can pull this off myself.’ ”

Lifeguards learn to scan a cove of bobbing divers and instantly detect discomfort or inexperience by the way they hold their heads above the water or cling to their float tubes. They urge some out of the water with polite coaxing. If there are no imminent signs of trouble, they hike on to the next cove, or drive farther up the highway.

“You are not expected to have drownings in Southern California,” Buck said as he stood on rocks near where another lifeguard nearly lost his life a few years ago in an ill-considered, unsuccessful rescue attempt in churning water. “Here, it’s sort of the norm.”

Abalone season opens each year on April 1. By early May last year, four men had died while searching for abalone — three of them on the same weekend, the other a week later.

On the last weekend of last season, during still weather in late November, a 67-year-old man from San Francisco was found in the same cove where Buck’s uncle had died more than a decade before. A day later, divers noticed an unattended float a few miles south, near Fort Ross State Park. Buck rushed to the scene, where he found a 57-year-old man from Oakland at the floor of the ocean with his weight belt on. He was the seventh and final casualty of the season.

“It’s not a matter of if some will die,” Murphy said in late May this year. “But when.”

Within two weeks, two abalone divers were dead near Mendocino. And on June 29, a 44-year-old man became the season’s third victim. He was sucked into an underwater cave. It took two days to recover the body because of high tides and strong swells.

Most abalone divers, of course, do not see their hobby as a risk, but a reward — a chance for companionship, to enjoy the ocean and, if all goes well, capture an abalone that others envy. Abalone diving in Northern California is celebrated, not feared.