Two eyes hover at the surface of the murky water, the only hint that a saltwater crocodile longer than a minivan is under the surface, patiently waiting for its prey.

When the moment arrives, the massive predator swiftly nabs the unsuspecting animal and drags it back into the water’s depths.

With most of their time spent under the murky surface, there's a lot we don't know about the underwater habits of saltwater crocodiles, which range widely throughout southern Asia and are called "salties" by Australians.

That's why National Geographic's Young Explorer Trevor Frost is using video cameras to document the hidden lives of salties near Darwin, a city in northern Australia.

Frost teamed up with videographer Melissa Lesh and developed a simple camera set-up: A GoPro attached to the top of an remote-controlled boat: "The kind you would find at a toy store or hobby shop," says Lesh.

The team duct-taped foam blocks around the GoPro to protect it against the crocodile's powerful bite. In 2015, the pair then released the camera into the rivers and billabongs—abandoned river channels or stagnant water.

The result: Amazing, up-close footage of salties chomping down on the camera nine times, offering a new perspective on how the powerful reptiles bite their prey. And their system worked: No cameras were destroyed.

Clever Hunters

As shown in the video, crocodiles are "quite innovative" hunters and use a variety of strategies to capture prey, says Charlie Manolis, chief scientist and saltie expert at the Australia-based company Wildlife Management International.

One strategy is ambush: Saltwater crocodiles sneak up on their prey—basically anything they get get their teeth on—before clamping down their jaws. Their bite is the strongest ever measured, generating over 7,000 pounds (3,200 kilograms) per square inch of pressure. That's strong enough to crush the hull of an aluminum boat, according to Frost.

Saltwater crocodiles have another superlative to their name: They're the biggest of the crocs. An average male is 17 feet (5 meters) long and weighs 1,000 pounds (450 kilograms). (Also see "Pictures: Biggest Crocodile Ever Caught?")

Another common hunting approach for these giants is to just "sit and wait." Hovering below the surface at the water's edge, the crocodile will explode out of hiding to grab approaching prey.

Crocodiles can also stalk their targets, following their mark over several days. "Crocs have got a lot of time on their hands," laughs Manolis, who was not involved in the new video project.

Educate, Don't Kill

Once hunted to near extinction, saltwater crocodile populations have recovered over the last 30 years in Australia, thanks to preserved habitat and more regulated hunting. While crocodile populations in the southern states are still recovering, the Northern Territory population now stands at roughly 100,000—a level last seen in the 1940s.

Crocodiles are the largest and heaviest reptile! Learn more amazing facts about these amazing creatures in this video from National Geographic Kids.

As both crocodile and human populations grow, however, crocodile attacks are on the rise, and some members of the public are calling for culling—or selective slaughtering—of the animals. (Also see "Explaining 'Saltie' Saltwater Crocodiles That Attacked Boys in Australia.")

But culling only "gives people a false sense of security," says Manolis. Instead, he says, the answer is educating the public about being safe around crocodiles, as well as more research into managing the reptiles. For instance, saltwater crocodiles can find their way home even after being displaced by hundreds of miles—a skill that's not completely understood but could influence how people manage them.

Manolis says that Frost and Lesh's video project could also help by filming more saltie behaviors.

Frost, who says he's staunchly against culling crocs, already has another trip in the works: He and Lesh will return to Darwin in December to capture more videos and photos of this impressive yet little-understood predator.