My husband and I travel every year to Venice , Italy. 3 years ago we bought the iMob pass for the vaparetto and it has been extraordinarily convenient. The original coat is, I believe, $50. One needs 2 passport size photos and to fill out a form for the card. There are a few centers in the city to do this...1 in Piazzle Roma. Another at the Rialto vaparetto stop. After purchasing the card one then pays for the number of tickets (vaparetto trips) he thinks he will need. The cost of theses tickets is the same as the locals pay which is a great deal less than the cost for tourist tickets. When the tickets run out it is easy to add more at any Tabachi in the city. Our friends were with us for 10 days. They bought a pass for 1 week @ $50 , their only option, but after that one week for almost the same amount ..they had to buy a 3 day pass. At that point it seemed to me that the iMob is without exception the best deal if one is in Venice for more than 1 week. The iMob is good for 5 years and can then be renewed
The IMOB 5-year residents's card is now €40. That is the thing with your photo of it. Once you have that, you can pay an additional€30 for a monthly pass, or you can buy 10-ticket carpets for account €12,, bringing the cost of a ride down to €1.20. But if you amortize the €40 for the IMOB it is not that much less than individual tickets. Of course, if you take 20 rides instead of ten, or return another year while the IMOB card is still valid, the value would be much better. But for the one-time visitor to Venice, probably not.
We just spent a month in Venice, and chose not to buy the IMOB card. We like to walk everywhere, so only used the vaporetto to access the islands, or for bringing our guests to the apartment near Rialto with their luggage. We grouped all our island trips ( San Giorgio Maggiore, Giudecca, San Servolo, Murano, Sant' Erasmo) and used a 24-hour pass for €20 to cover it all. We activated it around noon one day and it was good until until noon the next day.
They are currently "cracking down" on riding the vaporetto without tickets or passes, so whatever you choose, make sure you validate your ticket or pass before boarding. They have installed barriers at the Ferrovia stop so you need a valid ticket or pass to open the gate to the boarding dock. So far that is the only one we saw but that one went up sometime between Oct. 12 and Oct. 28.
If you board at a stop with no ticket agent or machine, you can still board. Just make sure you tell the boatman AS YOU BOARD that you need tickets. "Senza biglietti" will do it, or just say in English " We need tickets." After the boat is underway he will come and sell you a ticket for €7. Once when we boarded at an unmanned stop with our passes, he asked "Bigliett?" As we boarded, and we thought we ended to show our tickets, so we did. Ma Venetian explained to me that he was probably asking if we needed tickets, seeing that we were tourists ( my husband's large camera is a dead giveaway) and wanting to help us avoid a fine.