A 42-year-old man and his Seadoo are missing on Lake Erie.
The OPP say the man identified as Jason was part of a group of five people heading out from Rondeau Bay in Erieau Thursday afternoon before 3.
Each person had their own watercraft and provincial police say one vessel became disabled when it struck a hazard in the water.
Four of the boaters headed back to the marina, while one continued into the lake.
The search effort includes the Joint Rescue Coordination Centre, the Canadian Coast Guard, the U.S. Coast Guard and Chatham-Kent police and fire.
Provincial police describe 42-year-old Jason as white, five-feet-10 inches tall with a medium build and black hair and wearing a yellow lifejacket, red swim shorts and a beige t-shirt.