ET was first to visit the Baywatch set, where we talked to Zac Efron and Dwayne "The Rock" Johnson as the duo gushed over each other's hotness.

"Let's take a moment to look at the shape that this guy came in," Johnson told ET on the beach in Miami, admiring his co-star's enviable physique.

PICS: Dwayne Johnson and Zac Efron Are All Muscle as 'Baywatch' Starts Filming

Efron returned Johnson's compliment with praise of his own, saying, "This guy motivates you to work out. I started following him on Instagram. He's an animal!"

In the upcoming comedy, the actors play two unlikely prospective lifeguards who are vying for jobs on the beaches of California.

"I play Matt Brody," Efron said. "He's sort of like the brash, young recruit. He doesn't necessarily see eye to eye with Mitch on many things."

In the movie, Johnson plays Mitch Buchannon, the character David Hasselhoff became famous for on the '90s TV show of the same name. Johnson revealed how Hasselhoff was instrumental in the movie.

WATCH: Dwayne Johnson Talks 'Baywatch,' Zac Efron and Speedos

"I got to tell you, The Hoff has been amazing!" Johnson said. "From day one, he's been so supportive. He's like, 'If there's one guy who could play me, it's The Rock.'"

Baywatch opens May 19, 2017.