Shocking footage of a great white shark examining a small fishing boat off the coast of Busselton, Western Australia.

The video, filmed on April 28, shows the father-and-son fishing team commentating as the large shark circles the boat.

"My ten-year-old son had just caught a pink snapper," the filmer wrote online.

"After re-baiting his hook, he was washing his hands over the side and noticed a 16ft Great white Shark about 5 metres away from the boat swimming towards the boat.

"He screamed 'DAD' and brought it to my attention," he continued.

"After realising the shark was as big as the 16ft boat I was in, I cut all three fishing lines and told my son to sit in the bottom of the boat.

"I was going to get out of there ASAP but thought I would get some footage as it is a once in a lifetime chance.

"My son was very concerned, which you can hear in the video, and I soon left as the shark made a line for the boat and went under the boat."

Myself and my son were fishing 15Km off Busselton Western Australia. My 10 year old son had just caught a pink snapper. After re-baiting his hook, he was washing his hands over the side and noticed a 16ft Great white Shark about 5m away from the boat swimming towards the boat. He screamed "DAD" and brought it to my attention. After realising the shark was as big as the 16ft boat I was in, I cut all 3 fishing lines and told my son to sit in the bottom of the boat. I was going to get out of there ASAP but thought I would get some footage as it is a once in a lifetime chance. My son was very concerned, which you can hear in the video, and I soon left as the shark made a line for the boat and went under the boat.