VENICE — “You guys, just say ‘skooozy’ and walk through,” a young American woman commanded her friends, caught in one of the bottlenecks of tourist traffic that clog Venice’s narrow streets, choke its glorious squares and push the locals of this enchanting floating city out and onto drab, dry land. “We don’t have time!”

Neither, the Italian government worries, does Venice.

Don’t look now, but Venice, once a great maritime and mercantile power, risks being conquered by day-trippers.

The soundtrack of the city is now the wheels of rolling luggage thumping up against the steps of footbridges as phalanxes of tourists march over the city’s canals. Snippets of Venetian dialect can still be heard between the gondoliers rowing selfie-snapping couples. But the lingua franca is a foreign mash-up of English, Chinese and whatever other tongue the mega cruise ships and low-cost flights have delivered that morning. Hotels have replaced homes.