Video has captured the terrifying moment a woman was dragged into the water by a shark in Western Australia's far-north.

Melissa Brunning was hand-feeding a group of tawny nurse sharks on the back of a boat in Dugong Bay when one latched on and almost took off her finger.

The vision shows Ms Brunning right at the water's edge as one of the sharks swims in front of her. She suddenly topples into the water screaming as onlookers rush to help her.

"They have this incredible suction that they just suck the fish in, and as a result my finger ended up getting sucked into the shark's mouth as well," Ms Brunning said.

"It happened so quickly. All I could really focus on was the fact that my finger is gone. He'd clamped on it and it felt like it was shredding off the bone."

Despite the pain, the 34-year-old woman still has her finger.

Dugong Bay is a remote area, meaning Ms Brunning could not immediately go to hospital. She was visiting as part of a two-week holiday.

Ms Brunning's finger did not heal, and ended up so badly infected that when she got home to Perth she needed an operation to have it cleaned out.

An X-ray revealed the bite had fractured the bone and torn a ligament.

Ms Brunning now admits she made a mistake by getting too close to the sharks.

"It's a beautiful place to go to and it's an amazing opportunity if you can ever get there," the 34-year-old said.

"Just be mindful of your surroundings and don't feed sharks."

7 News