The man was not wearing a life jacket when he fell into the water around 4 p.m., police said. A companion on the boat attempted to find him, but the man did not resurface and the search was unsuccessful.

State police and other emergency crews responded to the bay, including wardens from the Vermont Department of Fish & Wildlife, the U.S. Coast Guard, and the Ferrisburgh Fire Department. The Coast Guard was expected to continue searching through the night, and the state police underwater recovery team and bureau of criminal investigations planned to join the operation Sunday morning.

The man's disappearance is under investigation, but police said there are no indications at this time that it is suspicious. His name is being withheld pending further investigation and notification of relatives.

Anyone with information that might assist in the case is asked to call state police at 802-388-4919.

The incident highlights the risks of cold-water boating on Lake Champlain, where water temperatures can be dangerously low even in milder months. Vermont law does not require adults to wear life jackets in all circumstances, but safety advocates urge boaters to wear them, especially when fishing alone or in small craft.