Now, to the underwater assault caught on camera. A scuba diver, ambushed by another diver, 50 feet below the surface. ABC's Neal Karlinsky has that story for us. Reporter: Rene um burger was taking... See More
Now, to the underwater assault caught on camera. A scuba diver, ambushed by another diver, 50 feet below the surface. ABC's Neal Karlinsky has that story for us. Reporter: Rene um burger was taking her camera underwater to document sea life countless times. But never in a million years did she imagine something like this. An alleged underwater attack. Diver on diver, off the coast of kona, Hawaii. I got to the surface, the first thing I said was, oh, my god, someone just tried to kill me. Reporter: One of the fishermen she was photographing, seeing a beeline, and ripping the regulator that allows her to breathe, right out of her mouth. I think sharks are less dangerous than this. Reporter: At 50 feet underwater, she could have easily drowned. Someone with less experience, surely could be dead. They could have panicked and not been able to find their mouthpiece. Reporter: Her friend, Robert, was also there and believes the driver who allegely attacked was trying to hide what he was doing. In his right hand was a scoop net full of baby yellow tangs. That's what we were there to document. And that's what he didn't want us to see. Reporter: Umberger believes that they're selling them to aquariums and pet stores. With a permit, fishing is legal. That's going to be branded in my memory forever, that look he was giving me. Reporter: This morning, authorities are studying the video and investigating. No word on whether charges will be filed in this rare underwater assault. For "Good morning America," Neal Karlinsky, ABC news, Seattle.
This transcript has been automatically generated and may not be 100% accurate.