St. Mark's Bell Tower or San Giorgio Maggiore Bell Tower?

I don’t think you would need reservations for the San Giorgio Maggiore tower. The view is indeed wonderful. Even if you don’t want a formal tour of the church, I recommend that you go in and look around - it’s a beauty. Also, it hosts exhibits of modern art by the Cini Foundation, so you never know what you might see in there. I happened to catch an exhibit of Jaume Plensa sculptures.

No idea how the May crowds would be, but when we were there in October a couple years ago, DH had only a couple minutes wait for the the S. Giorgio elevator. No reservation. He said the views were fantastic I stayed downstairs and toured the church.

Giorgio Maggiore Bell Tower- great views of Venice across the water. No tickets needed when we were there June 2023.

Thank you everyone for your very helpful advice. Would it be overkill and unnecessary to go up the St. Mark's Bell Tower and the San Giorgio Maggiore Bell Tower? The cost is not that much. Does the vaporetto run frequently to San Giorgio Maggiore? I guess I am wondering if we don't have time to make it over to San Giorgio Maggiore, then we at least have tickets for St. Mark's. I know; I am probably overthinking this.
Thanks!

Do both! That was our plan when we were in Venice in October, 2023, but, alas, the San Giorgio Campanile was closed the whole time we were there.

Reederman, thank you! Great minds think alike! :-) It didn't even occur to me that one of the bell towers could be closed. I've made my decision. I will purchase tickets in advance for St. Mark's Bell Tower and also plan on going up San Giorgio Maggiore Bell Tower. And if something prevents us from doing so, (it's closed; not enough time), then we will still have St. Mark's bell tower.

I have done both, they are different, I far preferred S Giorgio.

The vap is frequent and easy. And scenic, too.

Nigel, thank you. That's helpful to know the vaporetto is frequent and easy!

Go to both. I went to both twice and would do it again. There’s no law that says you can only go to one.

Marco, that is my plan, but nice to know more people think it's a good idea. I just bought our tickets for the St. Mark's Bell Tower. And I will set aside time to go to San Giorgio Maggiore. I actually prefer that we can't buy tickets in advance because this way we can choose the day and time that is the most convenient for what we are doing.

We did the San Giorgio Maggiore Bell Tower and found the queues to be almost non-existent, in October, and the views were superb.

We did intend to do St. Mark's too, but simply ran out of time with only three nights.