A great white shark has been captured on video feeding on a seal carcass just 500m off Geraldton.
Onlookers on boats used mobile phones to film the 3m shark ripping into the carcass.
English expats Doug Yeates, 44, and Paul Elliot, 42, were part of a small party on Mr Yeates' boat who witnessed the feeding frenzy on Friday.
Mr Yeates was taking his son Matthew Hancock, 21, and girlfriend Charlotte Bates, 20, on a cruise on the final day of the couple's three-week holiday from Britain.
Mr Yeates said he moved the boat closer after seeing something bobbing in the water.
Ms Bates filmed the shark just metres away from their boat.
In the first part of her seven-minute video, the shark grabs the carcass in its jaws.
Less than a minute later, it grabs it again and violently thrashes it for several seconds.
Mr Yeates said they watched the shark for about half an hour as it circled the boats.
The City of Greater Geraldton and the Department of Fisheries closed the beach a kilometre north and south of the site for 24 hours after the sighting.