There's no single right answer. It's like with restaurants. I try not to comment on a specific restaurant where I had a great memory and say that you should go there, because your experience and memory could be completely different, at least that's my opinion. All one can do is provide information so that someone can make a choice about what is right for them, and let them be responsible for making their own memories. I think it's better just help people know what they are getting into. I'd hate to be too specific like saying, "stay on Giudecca," then someone has a bad time.

The fireworks are not right in front of Della Salute, or right in front of San Marco. They are out in the open bay. That is for the same reason that authentic pizza is against the law in Venice (real pizza that is, cooked in a wood burning oven, as in Naples or Rome). A wood burning oven is so hot it would burn down the building it is in, so most of the pizza in Venice is cooked in a microwave. If the fireworks were close to Giudecca or Piazza San Marco and a bunch of hot cinders fell onto the old wooden houses they would burn down. So the fireworks are well out on the open bay.

The fireworks are HUGE. Anywhere near the water on either side, you can see them without trouble. I've seen fourth of July in Boston, which is > than NYC, which is > San Francisco. I don't want you to overestimate and then be disappointed, but in my opinion, the fireworks for Redentore beats them all.

As you probably know, they build a pontoon bridge to cross from Zattere to Della Salute. It opens on Saturday at 7PM after a ceremony involving local dignitaries and clergy. About a quarter of a million people attend this festival. Trying to get across that bridge will be like you taking the train in London at the height of rush hour unless you are there when it opens or not too much later.

On both sides of the water the locals mark out their turf, often the day before. Along the water front in San Marco people come out the night before and set up chairs, a picnic table, etc, they leave them there, and mark off what they consider to be "their turf" with tape, or some other marker. In the morning their stuff will be undisturbed, and they will have their spot. No one would dare to take it.

The tradition consists of three things; a mass, a picnic, and the fireworks. People cross the pontoon bridge to Della Salute to attend the mass that starts when the bridge opens at 7PM. But no need to worry, they have a mass every hour until the fireworks begin. If you don't want to do it on Saturday, Della Salute has plenty of masses that are part of the festival on Sunday. That takes care of the mass part, which is a nice tradition to participate in regardless of your faith, because the church is stunning.

The downside of staying on the Giudecca side after the mass to see the fireworks, unless you are staying in a hotel over there, is that the bridge closes at 11PM, almost an hour before the fireworks start. That's it. If you're not back over to the other side by then, you will be on Giudecca until the end of the fireworks, which is well after midnight. The pontoon bridge is maybe 15 feet wide. About 50 thousand people who chose to see the fireworks on the Giudecca side then have to make it across that narrow bridge. It will be the longest line you've ever been in. Don't even bother to try for at least an hour, until the crowd thins out.

Then, once you get across the bridge back to Venice proper on the Zattere, almost all of those people live somewhere on the mainland and are heading to Piazzale Roma for a train, a bus, a taxi, to pick up their car, or to a hotel near there. So, if your hotel is heading towards Piazzale Roma, with the Venetian narrow streets, you will be walking at a pace where you only take a few steps per minute. I can walk from the Zattere, where the pontoon bridge drops you off on Venice proper to the train station in less than 15 minutes. After Redentore fireworks, I'd estimate an hour and a half to two hours because of the crowds and the narrow streets.

Piazza San Marco is not a place where you want to be for any festival. Most of the quarter of a million people are there, or so it seems. It's OK for seeing the fireworks, but as I mentioned, most of the native Venetians will have come out and "claimed" their territory on the water front the day before. Those who didn't start showing up at around 6PM to stake out the best spots that are left. You will be back in the crowd in the Piazza. You can still see the fireworks, but to me, San Marco is a disaster zone.

Unless you get there real early you'll be way back in the crowd, unable to move, like being on a packed railway car with no air conditioning during insufferable heat and humidity, shoulder to shoulder with people, for hours.

How do Venetians comfortably wait for six hours or more for the fireworks? That's where the picnic comes in. It's picnic day. When they claim their spot along the water front well in advance, they bring food, wine, prosecco, and they picnic until the fireworks start. This you obviously cannot do standing packed like a sardine in Piazza San Marco, or at Giudecca where there is even less turf available to claim. The whole waterfront, from Piazza San Marco down to Giardini on the eastern tip of Venice is full of local Venetians sitting outside on chairs, with tables, having a picnic.

The more you go into Castello and the earlier you get there, the better chance you'll have of getting a water front or close to waterfront spot. Really, the fireworks are so huge that you can see them from anywhere near the Bay.

So you make a choice. Personally, I'd head down far enough into Castello, past Arsenale, where it will start to get sane, and where the local families will be. I'd invest in some cheap disposable chairs, maybe a blanket to lie on the floor. Definitely anti-mosquito spray or else you'll get eaten alive. Go to a store and buy plenty of food, wine, prosecco, and have a 4-6 hour picnic. And if you really want to blend in bring watermelon. It's the tradition for Redentore. And if you stay in a hotel in Castello instead of on the other side of town, you won't have to fight the crowds going to Piazzale Roma to get back to the mainland when it's all over.

Anywhere along the bay is fine for seeing the fireworks. There are no bad spots if you are reasonably near the water. It's that big of a show. I'd never want to be in the crowd on Giudecca trying to cross the pontoon bridge after the fireworks are over, well after midnight. And I would never want to be standing in San Marco Square like a sardine for hours and hours to see the fireworks.

On Sunday there are lots of boat and gondola races within the Grand Canal that are great fun to watch, so you might want to make your way down there. It's part of the festival weekend.