Great white sharks have been circling off a NSW North Coast beach where a whale was buried two days ago.

The 18-tonne humpback whale carcass was interred at Nobbys Beach in Port Macquarie on Monday because it was too big to be moved.

The dead whale being buried on Nobbys Beach, Port Macquarie. Credit:Mick Sheppo via Port Macquarie News

A nearby shark detector has picked up 21 great white shark movements since it was beached on Sunday, Port Macquarie Marine Rescue senior skipper Geoff Shelton told AAP.

"I definitely won't be swimming in the water - absolutely not," he said.