ENCINITAS, Calif. (NBC) -- Lifeguards are warning people to stay out of the waters along Encinitas, California after the reported sighting of a great white shark.
A local who surfs Beacon's Beach nearly every day reported seeing a 10-foot long shark in the waters Monday.
The sighting happened just before 3 p.m. near Neptune Avenue and Leucadia Boulevard.
"I've seen little sharks," said Brent Manion. "That one was big."
Manion said he was about chest-deep in the water toward the end of the beach when he saw the shark circle him and go under his board.
"I kind of froze up for a minute. Then a little wave came through and I was able to catch it," he said.
Manion estimates the shark was about 400 pounds.
"To have it come underneath you and see it eye to eye," he said. "The water is really clear right now. You could see him eye to eye. It's pretty creepy."
Once ashore, Manion reported the sighting to lifeguards who said they immediately knew it was a credible sighting of a great white shark.
"He's been surfing for years, so he also knew to rule out certain types of sharks based on features," said Sgt. David Brown, an Encinitas lifeguard.
Lifeguards are warning surfers and swimmers to stay out of the water a mile in each direction for 24 hours.
That's standard procedure following a confirmed or credible shark sighting along San Diego's coastline.
One surfer speculated the shark may have been interested in the thousands of anchovies he's noticed passing the last few days.
"Maybe that's part of the reason it migrated so close to shore in the inner waters," said Ari Marsh.
Regardless of the reason, Manion said he'll never forget what he saw.
"Still kind of freaked out about it," he said. "It's a pretty big shark."