Some questioned whether the deal would come to fruition. To the horror of historians, environmental campaigners and the remaining few Venetian natives, Venice seems to be preparing for even bigger ships. The authorities expect cruise liners to get even larger, and the proposed port would accommodate them.

Venice has faced an onslaught of tourism that has challenged the city’s character, clogged its narrow waterways and chased its local population away. There emerged no clearer symbol for the invasion of tourists than the cruise ships drifting, lunar-like, through the lagoon. They eclipsed church towers, famous views and, occasionally, the sun.

Even as tourist traps depended on the big ships for a new supply of consumers, local residents cursed the sight of them, and the Italian minister of culture and tourism, Dario Franceschini, who participated in the meeting, called them a “problem.”

The local authorities are hailing the new rules as a feat of compromise. They say they have addressed the concerns of residents, the requirements of shops and restaurants that live off cruise ship tourism, and answered the alarms raised by conservation groups who argue that the ships wreak havoc on the city’s already fragile and damaged lagoon.

The mayor, Luigi Brugnaro, said the decision made it clear to “the whole world that we have a solution.” Sounding a bit like a Venice travel agent, he added, “We can start to work seriously on planning cruises.”