I'm on the Veneziaunica site to buy vaporetti tickets for DH, DS, DD and myself. I'm confused as it refers to a rolling card for the DCs but I can't see where the option is to buy it. We don't want the museum add ons, just the transportation so that we can get one way from the airport and then travel about to the island etc over 48 hours. Can anyone help and let me know exactly what I need to buy please?