A professional shark diver has bravely demonstrated a "dumb" move that would get swimmers into hot water with sharks.
Drone footage shows the man just metres from two sharks in the ocean. They appear to be swimming away until a sudden splash from him triggers them to turn around and race back towards him.
The seemingly innocent move has been described by shark safety diver and marine biologist Andriana Fragola as "giving (sharks) the impression that you are injured or a prey item".
"Never splash around sharks," she warned in the Instagram video. "Animals in the ocean that splash are typically injured or struggling which means they are much easier to hunt. So if you ever encounter a shark while you are out enjoying the ocean, it is important to not splash and run away looking like prey."
"If you do this, sharks will typically be much more interested in investigating you and continuing to approach.
"Making eye contact with the shark and remaining calm are two very important things that could help you in any shark encounter."
She also warned the video in Hawaii was created for "demonstration purposes" and to "please not recreate".
"If you ever want to purposefully swim with sharks please go with a professional," she said in the video caption.
Social media users react to shark video
The footage from last week generated a lot of interest, with people calling the act a "prime example" of what can happen if you "panic" around a shark.
"This video is really cool," one person commented. "The immediate reaction to the splashing just shows how tuned their sense is for prey, but you can clearly see them slow way down when they notice that you, in fact, are not prey."
Others pointed out it's not always clear when a shark is nearby when you're casually swimming in the ocean. "Most of the people who are attacked by a shark don't see it coming," one person claimed.
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