Doctors say a surfer who survived a shark attack off the California coast Wednesday came within a centimeter of probable death.

Surfer Megan Hallava was surfing 65 miles north of San Francisco when the shark pulled her underwater. She says she hit the creature and it released her leg. She kept pounding the shark after resurfacing on its back.

The attack occurred off Salmon Creek Beach (search), a mile north of Bodega Bay (search), around 11 a.m.

Salmon Creek Beach has been the site of several shark attacks in recent years.

The 20-year-old woman told doctors other surfers screamed and splashed to scare the shark away.

Doctors believe the shark was 14 to 18 feet long. Santa Rosa Memorial Hospital (search) says an 18-inch bite mark goes around Hallava's thigh down to her calf, and came within a centimeter of hitting an artery. That could have meant eventual amputation, or she could've bled to death.

Hallava will have follow-up surgery Friday, but could go home early next week.