For years, a running joke among swimmers and surfers frequenting Los Angeles County beaches has been that they had more to fear from a mild sunburn or parking ticket than a possible encounter with a hungry shark.
But no one is laughing in New England, where a recent string of great white shark sightings has prompted beach closures.
Or in San Diego, where a swimmer was attacked and killed by a white shark in April 2008.
But in waters off local beaches, white shark sightings are relatively rare. Or are they?
Experts, pointing to relatively new tracking technology, say the massive creatures are migrating down the coast to Baja California, through Santa Monica Bay.
Waters off Los Angeles County beaches are also a congregating place for their offspring.
"There is a known occurrence in the summer of juvenile great white sharks in Santa Monica Bay," said Steve Blair, an assistant curator with the Long Beach Aquarium of the Pacific.
Blair said he was unaware of any shark attacks on humans in the area and it's difficult to pinpoint specific migration tendencies among white sharks - including why they tend to linger off local coastal waters.
"They're hard to study because they're so large - you can't handle them or catch them easily," Blair said. "And they're really not that common."
The species has been protected in California waters since 1994, according to the California Department of Fish and Game.
Experts say white sharks, which were added to international endangered species lists in 2004, like to feast on fish and seals, rather than oceangoers as depicted in the 1975 film "Jaws."
Most attacks on humans, they say, stem from curiosity or mistaken identity - sharks mistaking a wet suit-clad surfer for a seal, for example.
Revelations about the white shark's migration down the Southern California coast have been made possible through the efforts of researchers at the Monterey Bay Aquarium who have been tagging white sharks off Ventura and Los Angeles beaches and monitoring their movement.
Based on tracking data, sharks are swimming through waters from Santa Barbara south to Mexico, said Ken Peterson, a Monterey Bay Aquarium spokesman.
Since the program began in 2002, about 38 juvenile white sharks have been tagged off Southern California coastal beaches.
Waters off Will Rogers State Beach and Malibu have historically been known to attract white sharks, Blair said.
"There are certain areas they're attracted to," he said. "Any areas that include large populations of seals and sea lions."
Sightings have also been reported near San Onofre State Beach in northern San Diego County, Huntington Beach, the Channel Islands and throughout the Central and Northern California coast, including the Farallon Islands off San Francisco.
Despite the sightings, attacks on humans are rare.
But websites dedicated to forecasting surf are rife with user-submitted notices of alleged shark sightings throughout the Santa Monica Bay.
"They're frequently incorrect," Blair said. "Sharks are commonly misidentified."
Los Angeles County lifeguard officials said there have not been any recent shark sightings off South Bay beaches.
During the past two decades, there have been a string of shark sightings in waters off South Bay beaches, highlighted by a sighting in July 1978 of a rare hammerhead shark near the Manhattan Beach Pier.
In 2008, stunned whale watchers gathering at the Point Vicente Interpretive Center in Rancho Palos Verdes watched as a great white shark attacked a sea lion from underneath, throwing the animal in the air before crushing it with its jaws, according to a report in the Daily Breeze.
And in August 1982, two commercial shark hunters snagged a 16-foot female great white shark off Point Dume near Malibu.
The shark, too large to put aboard their boat, was towed to San Pedro, where a large crowd gathered to see the shark weighed. It died on the journey back to the harbor.
"All this just because of the movie `Jaws,"' one of the fishermen, Craig Williams, said while the massive creature hung on display for the growing crowd. "It's not really that big a deal."