State fire Capt. Josh Silveira says the man and his father were several hundred yards offshore Friday at Pebble Beach when the son was bitten in the right thigh.
Silveira says the man's leg was intact but the bite was serious. The victim was taken to a trauma center for surgery but there was no immediate word on his condition.
The beach was tagged with warning signs.
Silveira says there haven't been any recent shark sightings at the Monterey County beach.
However, in March a great white shark attacked a kayak in Monterey Bay, knocking the kayaker into the water. He wasn't bitten.