Transcript for Heroic Rescue from Hawaiian Shark Attack
And a terrifying encounter, one surfer in Hawaii is recovering tonight with a close call with a tiger shark as long as a car. She has the bite marks to prove it. Here is aditi Roy. His head on on my board. Reporter: Tonight, Mckenzie was in a shark attack. While off the coast of Hawaii. A tiger shark leaving behind bites on her hand and board. Her friend Brian Wargo was surfing nearby and raced to her rescue. Hitting the predator with his fist and grabbing the dorsal fin. I felt the shark shudder and at that time, he turned away. Reporter: Her left hand, punctured. And bracing for surgery. Shark bites, increasingly common. The number of great whites alone, up 42% since 1997. Just this week in Australia, a 20-year-old surfer escaping after wrangling with a great white. Tried to kick it off once and it let go. And grabbed on straight away again. Reporter: Scientists credit an increase in their favorite food, seals. And con sir investigation efforts to change their image. And making that tougher. Right now, I just feel really, really blessed and thankful that everyone is okay. Reporter: Aditi Roy, San Francisco. Lucky. We have much more "World news"
This transcript has been automatically generated and may not be 100% accurate.