This is the incredible moment it looked like a scuba diver came seconds away from being swallowed up by a giant whale shark.
Marine biologist Simon Pierce, 34, was diving with friends before they narrowly avoided being sucked into the whale shark's enormous mouth.
The 25-tonne beasts were feeding on billions of microscopic organisms called plankton when they approached the diving group.
Keen diver Simon, from New Zealand, whipped out his camera and caught the jaw-dropping snaps of the close encounter in the picturesque waters off Isla Mujeres in Mexico.
He told Caters News: "We noticed seabirds diving into the ocean, and drove the boat over to investigate.
"I was astounded to see thousands of tuna feeding beneath the surface on baitfish, with two whale sharks carving through as well.
"After I jumped in with my camera, I was surprised to see a few silky sharks circling underneath the action, but they kept their distance - as did I.
"Thankfully they're totally placid and often quite interactive with swimmers so I'm just relieved they wouldn't take the chance to swallow us whole."
Despite the sheer size of the whale sharks, Simon revealed they are actually harmless to humans and that he was thrilled to get up close and personal with the giants, some of which are more than 13 metres long.
"More often than not, if a whale shark swims over to say hello, I have to back off a bit to get their whole body in frame.
"The area is absolutely amazing and you can see whale sharks and manta rays feed on the surface through most of the day."
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