Speaking on TODAY on US TV, she recalled how she first bagged the role.
“It was my first time meeting [Zac],” she said.
“I had a chemistry test before I booked the role, so I had to do a bunch of scenes with him all in my bikini.”
Asked what state of undress her co-star was in, she added: “He was probably shirtless! But we had really good chemistry.
“He’s a great actor and he’s really funny. It was a joy to work with him.”
Daddario had previously spoken out on how she prepared for filming – saying she had revisited past episodes of the TV programme.
Speaking to Men’s Fitness, she said: “I watched a bunch of episodes of the show.
“We all took some creative liberties with the characters — we had a lot of opportunity to improvise and bring our own sense of humour to the roles.
“We could curse, or make a d**k joke, and no one said, “You can’t do that.”
She added: “The movie is completely off the wall—in the best way—and very self-aware.
“When Nicole Eggert found out I was playing her old part, she congratulated me on Twitter.”
Baywatch has, however, been suffering enormously with reviewers and audiences alike.
The film is out now in the UK.