Another shark sighting as search for remains continues

ADELAIDE - Shark sightings continued off Adelaide's West Beach today as search efforts resumed for the remains of an 18-year-old man taken by two great whites.

Police said two boats from the Sea Rescue Squadron reported a shark about 50m offshore from the West Beach Caravan Park this morning, not far from yesterday's attack.

The sightings came as the search continued for the remains of Nick Peterson, including a check of local beaches.

The teenager, from South Australia's Yorke Peninsula but who had been living in Adelaide, was grabbed by the arm and pulled under the water by one of the great whites as he was being towed by a boat off West Beach yesterday afternoon.

Mr Peterson's three 16-year-old friends aboard the boat watched in horror as the shark tore their mate in half, before another great white took his remains.

Searchers found Mr Peterson's surfboard late yesterday, but the victim was not sighted.

SA Sea Rescue Squadron spokesman Frasier Bell said one of the sharks was about five metres long while the other was about 4.5m.

"It (the first shark) tore him apart ... apparently it tore him in half and the other shark came in and took the rest," Mr Bell said.

His friends tried in vain to rescue their mate.

"They tried everything they could think of but unfortunately the sharks had taken him by that stage," Mr Bell said.

"They're in deep shock, they're a wreck.

Also today, police warned beachgoers to stick to patrolled areas of the Adelaide coast with temperatures in the city expected to rise into the mid-30s.

Surf life-saving clubs were also expected to put on extra patrols over the next few days.

The death of Mr Peterson was the second fatal shark attack in Australia in five days.

In Queensland on Saturday, Mark Thompson, 38, was killed at Opal Reef, about 75km from Cairns.

Mr Thompson suffered massive leg wounds in the attack and had a fatal cardiac arrest before paramedics could reach him.

- AAP