'GMA' Travel Diary: Jesse Palmer Swims at Night With Sharks

— -- "Good Morning America" correspondent Jesse Palmer traveled to the Bahamas for an up-close look at sharks in their natural habitat.

With the help of a guide, Palmer swam with sharks at night off the coast of Nassau and saw firsthand sharks’ heightened senses that give them 10-times better vision than humans in the dark.

“Sharks have an array of senses that allow them to adapt and basically hunt pretty any time they want in pretty much any condition,” said Palmer’s guide, award-winning shark cinematographer Andy Casagrande. “You know you throw in predators and darkness, and it is just a situation that humans try to generally avoid.”

The sharks’ incredible nighttime vision is due to reflective cells behind the retina, explained Casagrande, who will be featured this week on programs for Discovery Channel's "2016 Shark Week."

For Palmer, having only a human level of night vision left him feeling like he was “in a closet” underwater.

“It's crazy, it’s like you’re in the abyss,” Palmer said while on the night dive. “You can't see anything ... really can't hear anything.”

He added, “It’s almost like being in a closet underwater. I have no concept of where I'm at right now and what's around me. That’s the scary part.”

Palmer also saw firsthand the advantage sharks have over other prey, including humans, in the water.

“He's literally right beside you one second and then the next second disappears completely into the darkness,” he said of one shark. “It must be such an advantage over their prey, their ability to see, their ability to smell, the electromagnetic fields, all the different tools is why this is the perfect killer.”