Venice's gondoliers are being told to stop cutting off the tail end of their boats in a bid to help them squeeze under the city's bridges.
The shape and construction of gondolas is strictly regulated
High tides, said to be the result of global warning and heavy rains, have prompted some boatmen to chop off their gondola's distinctive iron "risso", mounted on the stern.
The double-s shaped decoration is said to represent the curves of the city's Grand Canal.
At least 20 out of Venice's 400 gondoliers are reported to have modified their boats, despite the strict regulations that cover the vessels' shape and construction.
Tourism at risk
The change has angered traditionalists who have called it a "barbaric act".
Franco Vianello Moro, president of Ente Gondola, the boatmen's governing body, said gondoliers were mutilating their boats and putting the city's tourist industry at risk.
He said some gondoliers no longer knew how to manoeuvre their boats.
Venice's Institute for the Conservation of Gondolas, which regulates the industry, is now warning boatmen that they have until 30 June to restore the gondolas to their original state.
In a letter to the city's gondola stations to be sent out on Monday, the Institute has put forward a compromise deal.
Gondoliers are being advised they can customise their boats to allow the risso to be lowered before difficult bridges.
"You cannot just wake up one morning and decide to cut off part of your gondola," a spokesman for the Institute told BBC News Online.
"Even though some will not like this, we hope they will understand," he added.