Footage of the near-miss was posted to YouTube on January 26 showing experienced fisherman, Al McGlashan and son Cooper reeling the fish to their boat.

"I've seen some wild things and had some close calls but this black marlin almost speared [Cooper McGlashan} in seconds," Mr McGlashan said in a post to Instagram.

"So lucky he still has his goolies," he said.

IN OTHER NEWS:

Cooper McGlashan sent the marlin back into the water before unhooking the lure.

Serious marlin related injuries are rare, with fishermen more commonly reporting a marlin bill through the leg, while wrangling the fish inside the boat.

The black marlin's bill is not used as a sword but their bills slash about to disorient schools of smaller fish.

"In all my time fishing I have never had such a close call and it all happened off Sydney," Mr McGlashan said.

Marlin can grow up to five metres long and weigh more than 700 kilograms, according to the NSW Department of Primary Industries.

Black marlin prefer swimming offshore in tropical and subtropical waters, but are "highly mobile" fish capable of navigating almost any depth of the ocean.