Harald Kvam measured the temperature of the tepid waters off Sai Kung yesterday, as he has almost every other day since the 1997 swimming season began last month. 'It's still around 24 degrees Celsius,' he said. 'We'll start expecting visitors when it gets to 26.' After scanning the horizon, then studying blue-water satellite images and the sonar screen in the cockpit of his 18-metre custom-built catamaran, the wiry Norwegian checks the shark nets separating bathers from toothy denizens of the deep. Nothing. Kvam is watching for sharks. He believes from past experience they will arrive with the warmer currents and the schools of tuna and stingray. The likelihood will rise sharply in about three weeks. But he has been keeping an open mind in case one comes early. On Thursday, residents reported seeing a three-metre shark swimming off Silverstrand Beach in Clear Water Bay. 'The only thing we know for sure is that the behaviour of sharks in Hong Kong waters is very different to their behaviour elsewhere,' he said. 'Here, we have seen three kills in less than three weeks. The rest of the world might see 25 in a full year.' Cue to the score of Jaws and Roy Scheider's mission to hunt the Great White terror after it chewed bathers at a quiet New England community. Four years ago, after Yan Sai-wah, 42, and Kwong Kong-hing, 61, were killed in early June attacks off Sai Kung beaches, a local hilarious sequel to Jaws played in Hong Kong, starring Australian shark hunter Vic Hislop. He bailed out abruptly two weeks later, having caught only a cold and food poisoning. But the sharks returned. On May 31 two years ago, physical education teacher Tso Kam-sun, 43, had his right leg bitten off to the waist. On June 2, hairdresser Lo Cheuk-yuet, 29, screamed in terror as his right thigh was mauled to the bone before he could be pulled from the water. Undeterred, people continued to take their morning dip outside the nets encircling the gazetted beaches. Wong Kwai-yung, 45, a housewife and early-morning swimming enthusiast, paid the price when attacked by a pack of sharks at Clear Water Bay First Beach on June 13. Her left leg and left arm were bitten off. She was the third known shark fatality in a fortnight. Between mouthfuls of Norwegian salmon and scrambled-egg sandwich, Kvam offered his opinion. 'I believe the big one is a Great White. But the teeth pattern in the victims was like that of a Tiger. 'The Great White has sharp teeth, triangular. The Tiger has smaller teeth and uses them like a saw blade when shaking victims.' This swimming season, having invested more than $6 million of his own savings in a vessel and sophisticated underwater tracking and diving equipment, he is driven by the challenge of finding a large shark in Hong Kong waters. Unlike Hislop, however, Kvam has no intention of killing it. He hopes to tag it and follow it for as long as possible from his long-distance catamaran he had built in Norway. 'We want to find out what is special about the sharks that come here and kill more than the statistical average,' says Kvam. 'Where do they come from and what is their behaviour in Hong Kong waters? Are there certain places in Hong Kong that attract them? How long do they stay? We can find the answers to a lot of these questions by monitoring the sharks with our sonar.' Kvam's lifetime interest in underwater life began as a young boy growing up next to the sea in Norway, beside a marine biological field station. 'I was taken out on their research vessels and they gave me special equipment to catch plankton,' he says. 'There was no problem having a kid around because I was useful. 'I sold fish and had saved up for my first boat by the time I was eight. 'In high school I would put out crab and lobster traps in the early morning and after classes. By the time I'd graduated I knew more about fishing and had more money than any of my friends.' Kvam studied to be a civil engineer and worked on North Sea oil rigs. He became an expert diver and signed up for a range of underwater projects from Nova Scotia to Rio de Janeiro. During a karate class back in Norway he broke fellow student Torgeir Herfindal's foot. The two became friends and are keen business partners in Marine Mechanic, responsible for netting most of the gazetted beaches in Hong Kong. He has tried to settle in a flat 'but I had to move out because the neighbours played majhong all night'. His home and workshop is a converted fishing boat in Aberdeen, crammed with cranes and tools and an assortment of paraphernalia. 'I had planned to make a very nice sitting room as well but I have not had time. Every year we take on more work.' His bid to find and trail a shark for more than 48 hours has already cost a personal fortune. If he succeeds it will become more expensive, with virtually no potential to get any of his money back. Kvam is unperturbed by financial logistics. 'In Norway we spend money on the strangest things,' he says. 'That's why we covered the North and South poles before anyone else. There are Norwegians much crazier than me. I'm doing this because it bothers me we have this problem with sharks and we don't know the answers. How can we protect our divers if we don't understand shark behaviour? If we don't monitor the sea, we will never know the answers.' Although it's still early in the season, he makes regular sweeps with his sonar, even off Tuen Mun, where the heavily polluted waters are churned by hundreds of diesel-leaking vessels a day. 'A Bull shark was caught off islands here last year,' says Kvam. 'They like bracken water and polluted areas. There have also been sightings at Kadoorie.' A Hong Kong resident since the late 1980s when he started an aqua culture project near Daya Bay, Kvam's new-found zeal for knowledge about sharks recently took him to the University of Miami's field station in the Bahamas where he dived with several different man-eaters. He has developed a 500-metre net made specifically to snare a large one. 'After sighting a shark I will have to circle it in the boat and wrap it up with the net as if it's a bag,' he says. 'I want to dive with it to make a video. I don't expect it to attack me. We will use a remote-controlled vehicle, like a very small submarine with four thrusters and a camera inside, to get close. If the shark is afraid of it, we'll try something else. 'We'll put a small electronic tag near the dorsal fin, or cut open the belly and insert a transmitter and sew it back together. It will only take a few minutes, then we'll let it go. It's more humane than to kill it just for the fins. We are talking about keeping it in captivity for minutes. If it saves a life, it's worth it.' Kvam reckons most of his time throughout May and June will be spent searching. In the past year he has arranged for eight of his staff to have advanced sonar training in the US. 'We have the know-how and the equipment to follow it for a couple of weeks,' he said. 'We'll have enough fuel to reach Singapore if it heads that way. I think we can get lucky.'