What it's like inside a Thai cave: ABC News correspondent Matt Gutman goes underground

ABC's Matt Gutman crawled, slid, crouched and wriggled through a Thai cave.

“What’s remarkable about this is that you’re crouching the whole time, and you get tired very, very quickly -- because you’re basically in a constant squat,” Gutman said in a video posted on ABCNews.com, noting that he was toting less than 20 pounds in his own backpack.

“Imagine doing it with 50, 60, 70 pounds of scuba gear? No wonder the rescue divers are completely exhausted.”

“All the divers we have been talking to are so wiped out,” an out-of-breath Gutman added. “These guys are completely exhausted.”

Gutman and an ABC News photographer ventured about 500 or 600 yards into the mouth of the dark, empty cave, a distance that he described as less than 1/10th the depth that rescuers have to go to reach the stranded soccer team.

Even with the aid of a flashlight and a television camera, Gutman took extra care to watch where he was going, particularly in very tight spots.

“It’s not easy to fit through here,” he said as he navigated one particularly tight spot with “scalpel-sharp” low hanging rock.

“Everywhere there are these pitfalls and hazards," he said, touching a slippery rocky wall. "You just bang your head on that and you’re out of commission for a while.”

At one point, Gutman and the photographer seem to barely flinch as they spot a subterranean bat. At another point, they come across something moving that they can’t even identify.

“What is that? A crab? A giant cockroach?” he asked.

The ABC News correspondent seemed humbled by the enormity of the challenges facing the rescuers.

“I’m a pretty small guy, and I can’t imagine having to go through something like this with ... tanks, underwater, trying to help these kids get through.”