Great White Closes San Diego Beach Rare shark sighting keeping swimmers away from Mission Beach By Rob Quinn, Newser Staff Posted Aug 26, 2011 2:00 AM CDT 0 comments Comments The lifeguard raised the alarm after spotting the big shark's fin protruding from the water a few dozen yards away. (Shutterstock) (Newser) – It's sizzling hot in San Diego, but the ocean's largest predator is keeping people away from the city's most popular beach. A 2-mile stretch of Mission Beach was closed after a lifeguard on a rescue board spotted a great white shark a few dozen yards away, the Los Angeles Times reports. Hundreds of swimmers were ordered out of the water. This is the first time a shark sighting has closed the beach "for as long as anyone can remember," a rescue department spokesman says. The beach will remain closed until authorities searching the area with boats and helicopters decide it's safe to go back in the water.