Melissa Brunning was standing on the stern of a yacht, feeding fish to a group of tawny nurse sharks, when one sank its teeth into her finger and dragged her overboard.
The attack happened while the 34-year-old woman from Perth was on vacation in Dugong Bay, a remote spot known for its sharks and saltwater crocodiles.
Tawny sharks are normally placid creatures but will bite defensively if they feel threatened.
Although she was quickly pulled back on board by her companions, Brunning initially thought that she'd lost her finger in the attack. "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."
Her finger survived, and Brunning emerged from the incident relatively unharmed. "I came up and I said, 'I've lost my finger.' And I couldn't even look at my finger because I thought it was gone, and I thought if I looked at it I'd probably go into shock."
Brunning said she was wrong to attempt to feed the sharks and cautioned others against doing the same.