A New Zealand pump repairman has caught the moment a shark exacted its ultimate revenge - sinking a stationary boat it was chained to.

The shark first appears in the footage chained to the boat, which is floating as normal. However, as the shark slowly lists to one side, so does the boat, taking shark and boat under with it.

"Pretty keen f---ing angler to land that puppy," Mike Freckling, who posted the footage live on Facebook, is heard saying in the video.

As the boat slowly takes on more water, Mr Freckling comments: "

Mr Freckling said the boat owners returned shortly after.

Ummmm, the question is... WHY was a shark chained to a boat?