A marine biologist nearly dived straight into the gaping mouth of a 16-foot tiger shark as she was preparing to enter the ocean off the coast of Hawaii.
A heart-stopping clip shows Ocean Ramsey preparing to jump off a boat and enter the water in Haleiwa when a shark named Queen Nikki approaches her.
Footage taken by the woman's husband, Juan Oliphant, shows the shark swimming towards the boat before coming out of the water and snapping at Ms Ramsey's fins.
The diver, who has worked with sharks for a long time and has known Nikki for over 20 years, backtracks but remains unfazed before saying: "Hi Nikki!"
When the shark gets back into the water, Ms Ramsey also prepares to jump back in.
She said: "It's just, like, 'That's Nikki,' you know, Queen Nikki, and she's such a fun and interactive shark.
"We were actually really excited for that moment. And I was just so excited to see her."
The clip, which went viral on Instagram, clarifies that the shark scientist was not attacked by Nikki.
Ms Ramsey told TODAY that she went into the water too fast and Nikki "totally reacted to that".
She explained: "I love that tiger shark. I grew up with that tiger shark, I think we were teenagers at the same time. And so I’ve known her for over 20 years."
The expert added: "I saw her and she was close enough, with enough speed, that it looked like she was actually going at maybe my fin tips.
"There (were) a bunch of little schooling fish under, so I could see her speed and I knew that I needed to back off in that moment."
Ms Ramsey, who works in shark research and conservation, said she received many inquiries after the clip went viral.
She wrote on Instagram : "Sharks are not monsters, they are important apex predators who need to be protected from the wasteful and cruel practices of shark finning, shark fishing, and bycatch
"Did you know that commercial industrial fishing fleets kill 9-12 other animals as bycatch for everyone targeted animal they kill. Industrial fishing fleets supply most grocery stores and restaurants with seafood."
Ms Ramsey, who is the CEO of OneOceanDiving and regularly takes people into the water to learn more about sharks, added: "Please help save sharks by writing to politicians, restaurants, stores, and companies who kill, buy, sell, or ship shark fins and byproducts and those companies who offer shark fishing or sponsor shark fishing tournaments."
