A shark attacked a man surfing off the coast of Oregon Monday -- but the victim, a trauma nurse, reportedly was able to direct his own first aid.

The animal bit 29-year-old Joseph Tanner on his upper and lower thigh, investigators said. Tanner had been surfing along Indian Beach at Ecola State Park at around 4 p.m. when the attack unfolded.

He told emergency personnel that the shark was “medium-big” and thought it could’ve been a great white shark but said he wasn’t sure, according to KGW-TV. The shark pulled him off of his surfboard and he swam to shore, police said.

"He directed his own first aid, what needed to be done, he asked us a lot of questions, what we were seeing, if we saw spurting blood," witness Jeff Rose said.

Tanner was stabilized at the scene and flown to a Portland hospital with serious injuries.

Rose said that a friend of his saw a shark attack a seal in the same spot about three months ago.

Authorities were investigating the incident.

The Associated Press contributed to this report.

Click for more from KGW-TV.