The former BBC political editor - who went on to take part in Strictly Come Dancing - is undertaking eight canal journeys for the ITV programme and examining the history of the route.
Barging Around Britain With John Sergeant is going to be filmed over the summer and screened later this year.
His travels will take him from Somerset to the the Crinan Canal in the Hebrides, which has been described as the world's most beautiful shortcut.
Richard Klein, controller of Factual ITV, said: "Britain's canal network is a true national treasure, full of great characters and rich in history. As they say, there's nothing half so much worth doing as simply messing about in boats, and what better way to do it than on an English narrowboat."