Hundreds of people in small rowing boats protested in front of St Mark's Square in Venice on Sunday, denouncing the proliferation of motorboats crowding the waters of the lagoon city.

The protesters also voiced opposition to the giant cruise ships that regularly sail close to Venice, a Unesco World Heritage site that has come under increasing strain from rising waters.

Critics say waves created by cruise ships and other large, motorised boats on the canal are eroding the foundations of the historic city, which regularly suffers from flooding. 

The protesters arrived on a flotilla of small, traditional boats, where the rowers stand as they plough through the water. "Stop the waves, stop the smog," said one banner flapping in the wind. In Venetian dialect, another said "Shame on those making waves." "Look out for the waves, they are drowning us," said a third.

Beloved around the world for its canals, art and architecture, in November Venice suffered its worst floods for five decades, with more than two-thirds of the city underwater and damage estimated at over a billion dollars. The high tides were blamed on climate change, but protesters say local authorities could be doing much more to protect the fragile city by banning big boats.

A decision was taken in 2017 to shoo away the cruise liners but it has yet to be enacted as alternative mooring sites are being developed. In August, ships weighing more than 1,100 tons were banned from certain waterways in Venice's historic center, after an accident in which a cruise ship collided with a dock. However, conservationists say the ban is insufficient to prevent underwater erosion and pollution.

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