Last Sunday, Mr Smith-Crallan, 25, plunged to his death when he attempted a jump from a platform more than 600 feet up an electricity pylon near Swanscombe, Kent, a popular spot for base-jumpers. His parachute is believed to have failed to open.
"It was his passion," his father, Tony Smith-Crallan, said yesterday. "He liked a challenge. He did it every weekend. We couldn't have stopped him because he was a grown man who did what he wanted to do.''
He said his son had always been "very careful" about his safety by always packing his own parachute and going with friends.
Kent police said there were no suspicious circumstances. An inquest will be opened later this week.
Mr Smith-Crallan is believed to be the seventh Briton to die base-jumping; about 90 are believed to have died worldwide.
The Swanscombe pylon, said to be tallest in Britain, is popular with base-jumpers because of its height and two platforms at 300ft and 670ft.
Gary Connery, a stuntman and one of Britain's leading base-jumpers, said he had jumped off the Kent pylon about 20 times since 1994: "It's quite a safe structure because the platforms overhang into space, unlike the face of a building, which just goes straight down."
It was the first time that Mr Smith-Crallan, whose nickname was "Basemonkey", had jumped from the pylon. Tributes to him have been posted on base-jumping websites. One said: "Base-jumping was what he loved, I can't imagine any other way he would have preferred ... Monkey will be missed by everyone who had the pleasure of meeting him."
Although the first recorded instance of base-jumping was a parachutist who leapt from the Statue of Liberty in 1912, the idea of it as a recreational sport was developed by the film-maker Carl Boenish. He filmed his first jumps in the Yosemite Valley in California in 1978 and coined the "base" acronym from the initial letters of building, antenna, span and earth, the four types of fixed points used by jumpers. He died jumping from a cliff in Norway in 1984.
The exact number of base-jumpers is not known, but dozens are believed to practise the sport in Britain. When a jumper completes a jump in each of the four categories, he or she can apply for a "base number". The 1,000th application worldwide was made a year ago.
Tony Smith-Crallan said his son had caught the skydiving bug as a teenager. "His grandmother died from cancer and he took part in a charity event. Paul did more than 400 dives and spent time in Australia because there are good skydiving places there."
He was briefly detained by police in January after he and a colleague leapt from the Blackpool Tower.
Mr Smith-Crallan had lived with his parents near Wokingham, Berkshire, since returning from Australia and worked in IT.
His father said the family were still coming to terms with their loss. "We are a close family. Paul was the kind of man who would do anything for his friends." Mr Smith-Crallan added that they would be reluctant to tell others not to attempt the sport. "While we wouldn't want this to happen to anybody else, I'm not sure that we have the right to tell anybody else not to do it," he said. "Those who take part take a lot of care and I think it is as safe a sport as many others."
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