(PORT HURON) -- Thousands of people could turn out for this weekend's Port Huron Float Down. Starting around 1 p.m. Sunday, people in tubes and rafts will hop into the water at Lighthouse Beach in Port Huron and float down the St. Clair River to Chrysler Beach in Marysville. Cody Kimball, who runs a website about the event, says he's expecting between 2,500 and 3,000 people. St. Clair County Sheriff Tim Donnellon is warning participants about using flimsy rafts. He also says people should bring paddles. That's important if winds push participants across the river toward Canada. Waterways will be closed to motor vessels. The U.S. Coast Guard, the St. Clair County Sheriff's Department and other agencies will be on hand for the event.