Dwayne Johnson and Zac Efron Are All Muscle as 'Baywatch' Starts Filming -- See the First Pics!

It has finally begun!

Baywatch with Zac Efron and Dwayne "The Rock" Johnson makes so much sense, it's hard to believe that it didn't happen sooner. But with the planned release date still over a year away, filming for the movie is just getting underway...

WATCH: Zac Efron, We Get It, You're Super Buff and You Work Out Like Crazy

Meaning we are just now catching our first glimpses of these guys in tight swimwear.

Johnson raved about his co-star after filming kicked off, writing on Instagram on Monday, " Day 1. My character "Mitch Buchannon" just gave @zacefron's character "Matt Brody" the all important beach speech about what it means to have manly "Alpha balls". Zac's ad-libbed responses were brilliant! Talented and great dude. World get ready to have some fun, 'cause the beach will never be the same again."

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

"We're excited about it," Johnson told ET last August about working with Efron. "I've known Zac for some time for years by the way, and this project has been in our wheelhouse and we're very excited to make the movie."

And it really seems like Efron is taking the role seriously, judging by how he might be in the best shape of his life!

Watch the video below.