And yet:
Cruise ships account for a large share of transiting passengers. In 2018
1,580,000 passengers transited by Venice, confirming its position as one of the Mediterranean's chief homeport. (
www.port.venice.it) About 600 ships visit, so that's 2600 each. I think this does not include crew. And most of them come in a six-month window, so that's about 3 per day.
But
The historic city, which has a population of 50,000 citizens, attracts around
25 to 30 million foreign visitors per year, according to the Italian tourist bureau. Less than a third of them stay overnight in Venice. And this is foreign tourists; it doesn't include Italians visiting for the weekend. (
https://news.artnet.com/art-world/venice-entrance-fee-tax-2019-1429798)
So cruise ships are responsible for less than 10% of the tourists, but get a lot of blame because they are very visible. Also, all 8,000 passengers from the average of 3 ships a day or more arrive almost simultaneously. Further, a moving cruise ship is pushing 50 million liters of water around, and a lot of that is eroding the lagoon and the foundations of the buildings. Finally, cruise ship fuel can have as much as 1000 times as much sulfur as is permitted in diesel fuel.
Most visits are terminal visits -- the ship is unloading in the morning and loading a new set of passengers in the evening. This is very lucrative and provides 4000+ jobs. But it also requires a LOT more transportation that less fragile cities could do better.
Alas, although tourism is the problem, it'll probably have to be the solution, too, as it's where the money comes from. DW first visited in 1985, and the Pacific Princess docked in front of St. Mark's. Our last
STAY in Venice, we had and AirBnB way out by the Biennale, and it was pleasant and didn't smell bad. In the evening, after most tourists left, it was not crowded, and we could see how life here could be beautiful. The visit after that was when we spent our hotel money (about 1/4 of what Venice would have cost) 40 km away in Padua, and took the bus in two days in a row. But we're pushing 70 now, and really there isn't a place to sit down, other than a restaurant, in the tourist areas. I don't think we're up to another visit.