As Labor Day weekend begins, many will be planning family trips to the beach.

Although, for those in San Diego, this picture might make them think twice.

A terrifying photograph shows the moment a Great White shark was spotted in a wave in Encinitas, California - just a few feet away from completely oblivious surfers.

© CBS8
Lurking: The shark, furthest right, swims through the wave the surfers try to ride
Gary Elliott, a passer-by who took the picture on Wednesday was convinced he had seen a shark - and the claim has now been backed up by marine experts.

'It looks pretty clear to me,' Mr Elliott told CBS8. 'It doesn't look like a surfer. It's not the silhouette of a board.'

The claim was initially disregarded by lifeguards at the beach.

Robert Veria said the photograph had, in fact, captured the moment a surfer duck dived into the wave with his or her knees bent.

© CBS8
Lucky escape: The surfer did not even realise the huge shark was beneath him
© CBS8
Brave or reckless? Surfers continue to ride the waves in San Diego despite the sighting
But marine experts have since confirmed that the picture is most likely to be of a shark.

Ralph Collier, from the Shark Research Committee, told CBS8: 'In my opinion, we are looking at the tail end of an animal that is... 10 to 12 feet, maybe a little more.

Officials said despite the sighting the beach would remain open for the weekend.

The stunning image was taken as two-mile stretch of coastline in La Jolla was reopened yesterday despite three confirmed sightings in a week along the San Diego coast.

© Associated Press
Huge: A surfer, top, catches a big wave in Newport Beach, California, yesterday
© Associated Press
Dangerous: Fans came out to watch the daredevils ride the massive Californian waves
Beaches had been closed after several people spotted a 12 inch shark fin on Wednesday near the Children's Pool.

Fishermen also found a dead baby seal off the Ocean Beach pier with shark bite marks.

Another two mile stretch of beach in the area was closes last week after a lifeguard saw an 18 inch dorsal fin.

© Associated Press
Fierce: The waves crashed down with huge force as surfers battled the conditions
The picture also comes as other astonishing images were taken of surfers hitting the waves in their droves in California yesterday despite being told to keep out of the water because of dangerous conditions.

Authorities issued warnings about waves pounding the central California coast that left a swimmer missing and caused a marijuana smuggling boat to crash onto a beach.

Lifeguards conducted dozens of rescues and the massive surf also caused some damage to the Ocean Beach and San Clemente piers.