The bite was reportedly on his wrist and forearm.
RELATED: Boy attacked by shark in Encinitas, will make full recovery
He's been identified as Ron Elliot, a commercial diver and documentary film maker who has been diving at the islands for more than 30 years, according to a NOAA Greater Farallones spokesperson.
VIDEO: Man rescued after being bitten by shark
Man rescued after being bitten by shark off Farallon Islands
His recent film "Near Miss" is about the time he was almost attacked by a shark. In a previous film that he was featured in, "Devil's Teeth," Elliot said, "I've been making my living diving for sea urchins since 1978. I know my wife when I first started diving out there, I knew she was wondering what would happen if something did happen to me and nobody else was on the boat. If I did get bit, the odds of somebody being there to help me are next to nil, but that doesn't stop me from doing what I'm doing."
It's believed Elliot was filming underwater at the time of the attack. He was picked up from a vessel called NorCal 1 and then then transferred to Stanford Medical Center by helicopter.
NOAA's spokesperson says that Elliot is reportedly doing alright and is being treated at the hospital.