There are few sights more likely to quicken an art historian's outrage than that of a cruise liner moored in Venice's Giudecca Canal, silhouetted against the fragile fabric of the buildings surrounding St Mark's Square. Around 650 of these floating giants, some displacing a localised tide of over 100,000 tonnes of water, enter the city each year. Their engines shake its foundations, spew pollution and deposit ever-increasing numbers of passengers. In 1990, there were 200,000 cruise passengers in Venice; in 2011, there were 1.8 million.
Action was taken by the Italian government against these massive intruders in November last year. Partly in response to the Costa Concordia disaster, the then prime minister Enrico Letta announced there would be a graduated reduction in the amount of shipping entering the city. The number of liners of more than 40,000 tonnes would be scaled back, and by November of this year there would be a ban on anything over 94,000 tonnes entering the Giudecca Canal. These largest of behemoths would instead follow a new route through the lagoon, which would involve dredging the Canale Contorta to accommodate the draughts of the floating hotels' keels. It was a win of sorts, but for Venice's growing "No to the Big Ships" movement two serious problems remained. First, there would still be as many as 475 cruise ships entering the city every year; second, the dredging would accelerate the loss of sediment from the bottom of the lagoon, further damaging the environment and the fragile timber piles of the buildings.