Livvy Dunne & Brooks Nader Spotted on 'Baywatch' Reboot Set For First Time

The "Baywatch" reboot is already bringing the heat ... and if these first pics of Livvy Dunne and Brooks Nader are anything to go by, we’re in for a seriously steamy watch!

Former gymnast Livvy was serving in a blue swimsuit, flashing a thumbs-up alongside swimsuit model Brooks -- who rocked a skintight, all-black look … both looking like they’ve already bonded before cameras really started rolling at the L.A. beach.

Just look -- big smiles, blazing sun, water sparkling ... the vibes were very much giving beachy bliss.

They didn’t waste any time getting started … sources tell TMZ Brooks has been grinding hard -- training twice a day with a swim coach for the past three weeks -- and just hit her first ocean session today, finally putting all that prep to the test.

TMZ broke the news they’d joined the reboot, with sources telling us Livvy’s playing Grace and Brooks is stepping in as Selene.

The rest of the lineup is stacked too -- Stephen Amell as Hobie, Jessica Belkin as Charlie, Noah Beck as Luke, Shay Mitchell as Trina, Hassie Harrison as Nat, Thaddeus LaGrone as Brad, and David Chokachi as Cody. In fact, many of them hit the waves for training earlier this week!