SYDNEY (AFP) - An Australian woman raced into the water and dragged to safety a swimmer who was being attacked by a large shark which had already removed "huge chunks" from his leg, reports said Sunday. Joanne Lucas heard swimmer Jason Cull's cries for help as she arrived at Middleton Beach in Western Australia early on Saturday, and immediately dove into the water to help him. "Instinct just kicked in," she told The Sunday Telegraph. "I didn't even have to think about it, which is amazing really. I just thought I had to get in there. "I got to him and he said, 'Thank God. Thank you so much - a shark has attacked my leg.'" Lucas told the paper she concentrated on getting the injured Cull and herself the 80 metres back to the sand before the shark "He had huge chunks taken out of his leg, his calf and the knee," Lucas said of the 37-year-old schoolteacher who had been swimming with dolphins when he was attacked. Cull was in a stable condition in Albany Hospital after surgery for lacerations to his left leg. Middleton Beach, on the far south coast of Western Australia, was closed Sunday as surf rescue volunteers and fisheries officials tried to drive three white pointer sharks out to sea.