He says Bait is part-disaster movie, so using the tsunami was essential to the story, but as with any film, it's hard not to make a connection to real life.
"Look at movies, people get shot, people get run over," he says."It doesn't matter what it is ... even if it's a romantic comedy, you can't avoid it."
Bait features a cast heavy on former Home and Away stars, including Lincoln - son of league legend Wally - Lewis, who is trapped with Cariba Heine in a flooded carpark one floor down.
While it meant they filmed most of their scenes in a submerged car, it didn't keep them dry.
"We were sitting on sopping wet seats and standing on top of the combi in a tight white T-shirt and black bra," Heine says.
"She's talking about me actually," Lewis jokes. "You'd be surprised at how much it makes a man feel sexy."
In all seriousness, he says as soon as they would start to dry off, they would get the order to jump back in the water.
In the short term, it meant chlorine rashes and pruny-looking fingers, but with no adverse affects long-term ... except maybe a bit more fear of the beach this summer.
Rendall says while there are scares, Bait is more of a fun popcorn movie and doesn't take itself seriously.
"People mention Jaws," he says. "[Jaws is a] masterpiece and we weren't intending to make a film that was any better than that. There's no way. This is a different style of thing."
Lewis says he knew Bait had a funny tone from the script, "and we tried to make use of every single possible joke that [came] our way".
Movie preview
What: Bait 3D
When: Opens tomorrow.
- AAP
