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