A man has managed to capture the moment he was attacked by a reef shark, using his head camera.
The footage shows the spear fisherman fishing in Key West, Florida over the weekend before an 2.43 metre reef shark approaches him.
Parker Simpson said he often encounters sharks on spear fishing trips but said this one "came out of nowhere".
The shark initially charged towards his friend and diving buddy but then turned on Simpson.
The animal bit his leg and cut the speargun line.
He groans in pain and bravely tells his friends to "go, get away" and continues to look for the shark while holding his bleeding leg.
Simpson told Storyful that he thought the shark was trying to get the black grouper he was holding but the predator kept coming even after he dropped his catch.
He said he lost more than two pints of blood after the shark tore through the skin, muscle and the tibial artery on his leg.
Simpson's friend drove him to the hospital where he spent four hours.