Story highlights Brett McBride is a shark wrangler, freediver, big waver surfer and..."superhero"

The captain of science vessel Ocearch has helped tag over 100 sharks across the world

After appearing in TV series "Shark Men," McBride gained celebrity status

He says world must stop shark finning, which kills 70 million sharks each year

Imagine you're sitting at the bottom of the ocean, amidst 500 sharks in a feeding frenzy.

Would you: A.) Swim to the surface as fast as your trembling legs could take you. B.) Find a weapon to arm yourself with. C.) Fall asleep.

Brett McBride fell asleep. For a minute. While hundreds of three-meter-long Galapagos sharks swarmed around him during a feeding frenzy off the coast of Costa Rica.

The 46-year-old shark wrangler doesn't suffer from some kind of severe narcolepsy. Instead, he was merely proving a point -- these fearsome predators aren't going to be interested in you, if you're not interested in them.

"It would seem crazy, but it's not. It really just shows you how bad a rap sharks get. They're just like any other fish," said McBride.

"Galapagos sharks, they're not big mammal eaters. It would take them probably hours to get the courage up to attack you if you were adrift at sea."

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Even if Galapagos sharks had the temperament of a kitten, there are perhaps few people willing to doze off in their midst.

But then, McBride isn't like most people. The captain of science vessel Ocearch spends his days handling sharks as part of one of the largest tagging projects ever undertaken.

Shark Men

The Ocearch team of scientists and sailors are on a mission to electronically tag sharks, in an effort to build a global map of their migration, breeding, and birthing habits.

It's a huge operation, which involves luring the formidable creatures onto a converted fishing vessel, before attaching $10,000 worth of satellite tracking equipment, taking blood samples, and even conducting an ultrasound -- all within the space of 15 minutes.

Since it launched in 2007, Ocearch has tagged over 100 sharks. But it wasn't until National Geographic started featuring the team in hugely successful TV series "Shark Men," that they became something of prime time celebrities. And the most fearless shark man of all? Brett McBride.

It's McBride's job to guide the sharks onto the ship's platform, which lifts out of the ocean much like a giant cradle. Often he'll have to jump in the water with the predators, maneuvering them into position with his bare hands. Later he places a towel over their eyes to calm them, and puts tubes of water in their monstrous jaws to irrigate the gills.

"When I'm dealing with the shark up close, when I've got my hands on it, those are the times where there's not fear going on, but a real focus -- I'm watching that shark's every twitch, every move," he said.

"I know where he's going to be half a second from now, which is more important than being able to pull away when he lunges towards you."

Superhero

It's perhaps unsurprising that McBride has been labeled a "superhero" by fans of the show. This, after all, is the same man who in one episode leaped into shark-infested water to untangle a cable from the boat's propeller. The same man who dives 35 meters on a single breath of air while spear fishing. The same man who surfs 10-meter-tall waves in hurricane conditions.

Yet when I ask him about his superhero status, the father-of-two rather charmingly clams up, saying: "You've kind of got me blushing."

But in a sense, McBride does have a super power -- the ability to suppress fear.

"When I'm in the water and see a shark, I can keep my fear completely under control, which helps me because they feel your heart beat, your sweat," he said.

"Your nervousness is very apparent to them. They can sense electrical impulses and vibrations."

A fine balance

Growing up in San Diego, on the Californian coast, McBride started fishing when he was five years old and working on boats when he was 11, adding: "From the time I was big enough to hold a scrub brush, it was time to get to work."

McBride says he isn't a shark wrangler for the adrenalin rush. He believes Ocearch's scientific work is an essential part of protecting these ancient predators -- and other fish in the sea.

"Over 70 million sharks a year, world wide, are killed for their fins (often used in soup), and it's devastating the balance of the ocean's ecosystem," he said.

"If we can create a whole new generation of scientific minded and conservation-minded kids, then we have a chance of winning this global war against shark finning -- and keeping the ocean sound and stable."