Despite their reputation as Australia's most feared yet fascinating creatures, little is known about the great white sharks that live, breed and feed along our coast.
Hugh Edwards knows more than most about these mysterious animals after decades of research and close contact with some of the ocean's deadliest predators.
Great whites still hold fear and fascination for him.
It has been more than 35 years since Edwards first came face-to-face, and almost head-to-mouth, with a great white.
He was dangling terrified in a metal cage in the blood-tinged waters at Albany's whaling station.
Since then, the Perth author has been studying the great whites off WA's coast and has spent hundreds of hours underwater observing them.
Many West Australians have become more fearful of sharks, shocked by the tragic deaths of four men in attacks along WA's coast in 14 months, three of them in just seven weeks between September and October last year.
Edwards said great whites were more prevalent in WA waters these days, which could explain more sightings and attacks.
"We know so little about sharks," he said.
"It's too hard to generalise. But I think from my experience over the years we never used to see great whites and now they are sighted regularly in the metropolitan area and all along the coast."
The 78-year-old believes one shark could be responsible for the recent spate of fatal attacks.
"A shark attack is an aberration in any case, but any great white attacks in particular tend to come in cycles so it's unusual for a shark to attack, but having once done so it might make sense for that shark to be involved again," Edwards said.
He believes it is possible one "rogue" shark was involved in the recent deaths, particularly those in metropolitan waters.
Swimmer Bryn Martin was taken off Cottesloe on October 10 last year, scuba diver Thomas Wainwright was killed off Rottnest Island 12 days later and snorkeller Brian Guest disappeared off Port Kennedy in December 2008.
But opinions vary on the "rogue shark" theory.
Fisheries senior shark researcher Rory McAuley said after Mr Guest's death there was no evidence to show individual sharks had been involved in repeated attacks on humans.
NSW shark researcher Vic Peddemors said he did not believe great whites developed a taste for human flesh because humans tasted very different from marine mammals and did not have the fat layer which sharks liked.
Mr Wainwright was the third person to be fatally attacked in WA in seven weeks.
Bodyboarder Kyle Burden was killed the month before near Bunker Bay in the South West. With sharks, on average, usually responsible for one death nationwide each year, it has been an alarming trend.
After three years spent diving with great whites in Albany in the 1970s to research their behaviour, Edwards is convinced that sharks are intelligent creatures.
He writes in his new book, Shark, that the first great white to approach him in his metal cage had poise, confidence and intelligence.
"(There was) a feeling that they were measuring, assessing us, and a decision would be made any moment," he said.
Edwards believes this intelligence means a great white shark does not, as is often suggested, mistake humans for their favourite food - seals.
"I'm sure that great white sharks are very intelligent and I'm sure they know all about us," he said.
"They know what we are. When we are taken, it's not a mistake.
"They've decided they are going to eat this funny thing whatever it might be and they go for it."
Despite alarm over the recent tragedies, Edwards said he did not think shark nets should be installed along WA beaches because the number of shark attacks was not high enough to justify the cost and environmental toll.
In 26 years, Queensland's nets killed 30,630 sharks, 520 dolphins, 576 dugongs, 3656 turtles and 13,765 stingrays.
Since 2000, 23 humpback whales have become entangled in the nets.
However, shark attacks on humans at beaches where nets are installed have reduced dramatically.
Asked why there are more shark attacks and sightings in WA, Edwards suggests a revived and thriving seal population on the south coast and around Rottnest Island may attract sharks.
Even this self-taught shark expert, who has learnt through experience and shared knowledge, is fearful of becoming a great white's next target every time he steps into the ocean.
"I go swimming down at Swanbourne and I always think about it (and) look around," Edwards said.
While his cage-diving days are less frequent, Edwards still has a fascinating career as an author and shipwreck searcher.
But it is a long way from the boy who "scuba-dived" off Rottnest in 1946 with a gas mask and a hose.