California Fish and Wildlife regulations say that lobster divers must use hoop nets or their hands to capture lobster during lobster diving season, which started at 6 a.m. Saturday.
Giles says the rescuers were an off-duty police officer, an off-duty and a third person who were also lobster diving.
Calls came in about the attack around 7 a.m., the San Diego County Sheriff's Department confirmed.
Encinitas Lifeguard Captain Larry Giles said: "He was conscious, he was above water, and the bystanders were able to get him up on the beach. and he was talking all the way to when he was being transported".
The boy was brought ashore and flown by helicopter to a trauma centre.
Hammel said he thought the boy was just excited when he first heard him shouting. "His whole clavicle was ripped open", Hammel said". Hammel said he heard screaming and then realized the boy was yelling, "I got bit!"
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Hammel also said he couldn't have helped the teen without the help of his friends and the dozens of others on the beach. 'We told him he's going to be okay, he's going to be alright - we got help.
A boy, 13, was diving for lobsters when he was attacked by a shark off the southern Californian coast.
Several miles of the beach have been closed by authorities for 48 hours and a surfing competition has been cancelled.
The boy was pulled onto a kayak and rushed to shore, where footage showed him being treated by lifeguards before a helicopter lifted him to a hospital.
Since the incident, there hasn't been any shark activity, according to Giles.
Giles said there was a non-fatal shark attack earlier this year at Camp Pendleton, north of Encinitas.