A recent viral video showing the encounter of a diver and a great white shark that included a "handshake" between the two didn't happen exactly as it appeared, people involved in the incident have revealed.
In the video, the shark – one of the largest ever filmed – appears to "high five" a dive master hanging outside of a shark cage.
Since a shark would have no idea of what the common human gesture might mean, it raised the question of what exactly the shark was doing with its fin.
It turns out it wasn't the 22-foot-long shark but rather the diver who was the initiator of the contact.
Joel Ibarra, the dive master of an ecotourism boat, was in fact trying to keep the creature from making contact with the shark cage and possible harming itself.
"The dive master was pushing the shark away — it has a big laceration on the right side," explained shark researcher Mauricio Hoyos Padilla, head of a nonprofit group focused on sharks and other open-water species. "It was really close to the cage, and they have pointy ends. It is so big it couldn't turn properly. So he was trying to push her away, because he didn't want her to get hurt."
To do so, Ibarra partially exited the cage — a move experts say was not as dangerous as it might appear.
"Coming out of the cage like that is not as risky as it might seem," said Carl Meyer of the Hawaii Institute of Marine Biology, who studies sharks as part of his research on coral reefs.
"The diver waits until the head of the shark has gone past, then climbs out to touch the pectoral fin," Meyer said, of what appears in the footage filmed for the Discovery Channel. "At that point, the shark can't turn and get the diver. The diver keeps watching the white shark and then ducks back into the cage."
Hoyos Padilla has spent 13 years studying great white sharks off of Mexico's Guadalupe Island, a known breeding ground for the predators of the Pacific Ocean.
Wanting to observe the behaviors of pregnant females, he asked the operators of ecotourism boats in the region to let him know if they spotted one.
That's how the huge female shark the researchers have dubbed Deep Blue was located.
The encounter between Ibarra and the shark occurred as they followed her in Hoyos Padilla's research boat for almost three hours.
Her great size suggests Deep Blue is probably more than 50 years old.