Sharon Chan and Ben Wong were filming for TVB new series Midas at Tso Wo Hang Pier in Sai Kung.
For a scene, Ben personally drove the motor boat and got into a minor accident with another boat, reports Oriental Daily.
He almost injured Sharon's male stunts double, while Sharon shouted: "Scared me to death, a murder!" when she saw the crash.
Sharon later joked: "I don't film these types of scenes, my poo will come right out!"
Ben expressed at the time there was about two seconds when he didn't know how to react.
"Initially I wasn't scared, but then Sharon screamed.
"Actually when I was parking the boat, there were waves that pushed the boat forward.
"So was the owner of the motor boat upset? "No, because there were life jackets in the boat. I didn't actually hit anything.
"Later, the crew got back on the boat and went out to the sea for an in-water scene.
"When Ben pulled Sharon up from the water, another minor accident happened, she accidentally bumped her head on the boat."
However, Sharon joked after her head bump, she got smarter: "I'm always hurting myself, its not a big deal."
Asked if Ben scared her? She said: "Yeah! When the camera rolls, I look very brave, but behind the cameras I'm myself."
Also, Miriam Yeung and Taiwanese actor Vic Zhou (Zai Zai) were also shooting an in-water scene for Johnnie To's new film in Sai Kung.
They were shooting in the water for about an hour. Miriam shouted at Zai Zai in the water: "Oh no, oh no!"