'He will be horrifically missed': Tributes for British diving instructor killed by shark in Sydney

ITV News Correspondent Martha Fairlie reports on the tragedy surrounding the first fatal shark attack in Sydney since 1963

A friend of the British driving instructor who was mauled to death by a great white shark in Australia has said he will be "horrifically missed" as he was "one of the people who makes this earth better".

Local media named 35-year-old Simon Nellist as the victim of the attack, just off Little Bay in east Sydney on Wednesday afternoon.

Mr Nellist, who had been swimming just offshore when the great white attacked, was said to have been training for a charity ocean swim this weekend when he was attacked from below.

'The news hit us like a truck because he is really one of the people that makes this earth better,' Della Ross, Mr Nellist's friend, said

It's been reported that the experienced diving instructor, who was living in the Wolli Creek area of Sydney, grew up Cornwall before moving to Australia and was engaged to be married.

Paying tribute to the instructor, friends said he "loved the water" and was intrinsically "connected to the ocean".

Della Ross, Mr Nellist's friend, told broadcaster 7NEWS Australia that word of the tragedy hit her "like a truck" as he was one of the people who "makes people's lives lighter".

Ms Ross, who regularly went on diving trips with Mr Nellist, went on to describe her friend as a very "patient" and "calm" person, who was understanding of people's fear of the water.

She described the incident being all the "more horrible" because he used to teach people to "respect the ocean" as he said it was the shark's territory.

'He told people that they have to have a healthy fear of the ocean'

Australian authorities are scouring the water off Sydney’s eastern beaches in search of the shark responsible for the city's first fatal attack in almost 60 years.

A witness described the horrific incident to 7NEWS Australia: “He was swimming across the headland and the shark came at full speed,” he said.

“It’s very hard to talk about it, because it happened like 10 metres off the rocks.”

The attack has prompted warnings for swimmers not to enter the water at 13 of Sydney’s beaches, as lifesavers patrol a 15.5 mile stretch from Bondi in the city's east to Cronulla in the south to locate the shark.

Shark attacks in Sydney are rare as the city has long had nets and other deterrents in its waters.

The attack was the first shark-related fatality in Sydney waters since 1963.

On Thursday, the Department of Primary Industries said that based on provided footage the species responsible was likely a great white shark of at least three metres in length.

"This person had suffered catastrophic injuries as a result of the attack and there was nothing paramedics could do when we arrived on scene,” New South Wales state Ambulance Inspector Lucky Phrachnanh said.

New South Wales Police told the PA news agency the search for Mr Nellist's remains would continue at sunrise on Friday.