Two men fishing off Preston Beach, south of Dawesville, had a scare yesterday when a 4m white shark nudged their 3m dinghy.
It is not known whether the shark was being aggressive or how far offshore the men were when they encountered the predator.
One of the men told water police they quickly returned to shore.
The sighting was reported about 1.20pm.
A windsurfer also told authorities he saw a 4m white shark about 1.3km from shore in South Passage, Lancelin, about 6pm on Tuesday.
The sightings come just days after two tagged 3m great whites repeatedly set off acoustic receivers at Ocean Reef and a tagged shark activated a beacon at Garden Island.
The WA Conservation Council said the sightings were not surprising because more sharks visited between October and December, attracted by migrating whales and recovering snapper spawning in Cockburn Sound.Fisheries advise divers sighted 5m white shark, 1 km offshore, Flinders Bay, Augusta, at 1340.
Fisheries advise 2nd hand report of possible shark 50m offshore Secret Harbour SLSC (yesterday 5pm). Fisheries investigating.
Fisheries advise sighting of 5m shark at Jays Beach (close to shore), Augusta, at 0950.
Fisheries advise sighting 5m White shark between Coffin Island and Cape Vancouver, near Two People's Bay reported 1204
Fisheries advise sighting of 4m white shark at Stanley Island, near Parrys Beach, West of Denmark, at 0800. Reported 1340
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