Despite their fearsome reputation, hammerheads are some of the most shy and sensitive sharks in the sea. Their elusive nature makes diving with these "ocean ghosts" a challenge, but thanks to underwater camera traps, we're starting to see them in a whole new light. 

By placing a GoPro near the Darwin Arch of the Galapagos Islands – a known hammerhead hotspot – marine biologist and photographer Dr Simon J. Pierce managed to capture this beautiful clip of a scalloped hammerhead (Sphyrna lewini) in action. 


 

"Hammerheads are amazing to watch in the water," he says. "Few sharks come together in such large groups, and there aren't many places where this happens."

Here at Darwin Island, scalloped hammerheads spend their days leisurely swimming through the up-currents in search of "cleaning stations", where smaller fish gather to pick dead skin and parasites off the sharks. 

"I think Darwin is the best dive site in the world," says Pierce. "I was rapt to get the opportunity to dive with these sharks, as scalloped hammerheads are a globally endangered species, and there are too few places where experiences like this are still possible."

While their large fin-to-body ratio makes these animals particularly vulnerable to the shark-fin trade, sport fishing (and bycatch) are also a big problem, and the sharks' stress sensitivity is a major point of concern for conservation biologists. The animals are extremely powerful, and known to put up quite a fight on the line. Elevated stress levels can cause the sharks to die, even after being released.

Luckily, Darwin Island falls within the Galapagos Marine Reserve, where management authorities work hard to enforce fishing bans, Pierce explains.

What's it like to swim with a school of these elegant predators? Our crew finds out on a dive in the waters off the coast of Mozambique: