This is the moment when scores of hammerhead sharks swim peacefully past a group of scuba divers just metres away.

The underwater footage shows around an estimate of 100 sharks swimming casually though the deep blue sea at South West Rocks on the mid-north coast of NSW.

Peter Yarwood, who caught the event on camera, said that his closer encounter with the school of hammerheads couldn't deter him from his passion of diving.

'It was completely unexpected to see that many hammerheads around here but it was awesome and a pretty exciting day,' he said. 

'We rarely get hammerheads in the area and it was a very off chance that they'd come around but I'm pretty happy about that.