Sugababe Ewen has confessed that she can barely swim and is scared of water, while TV presenter Falconer admitted that she was concerned about what outfit she would be told to wear.
"I can't really swim, I've only just learnt. I was never taught to swim," Ewen told The Sun. "I'd never ever been in deep water as I hate it and it terrifies me. My mum always told me, 'Don't go in the sea or you'll drown'. I've grown up thinking I'll drown if I go in the water. I can't get it out of my head."
The singer said that producers insisted she wear a bikini during her diving, despite her concerns that her bikini bottoms could come off and that it may be caught on camera.
"They obviously thought it would make good TV if mine came off," she joked.
Falconer had similar concerns, commenting: "The costume lady mentioned bikinis and cut-out swimsuits, but I'm very hesitant to commit. I don't want to wear a granny swimming costume but I don't want to expose myself on live telly either."
The first episode of the TV reality show will feature Falconer, Ewen, Omid Djalili, Jake Canuso and Helen Lederer all competing against each other with the help of Daley.
Splash!, which is hosted by Vernon Kay and Gabby Logan, starts this Saturday (January 5) at 7.15pm on ITV.