I never used Viator nor heard of them before. I booked a tiki party boat for 4 for for a small Bachelorette party. I booked 3 weeks in advance and the morning of, I log in to retrieve/screenshot the tickets for my party. I learned that morning that my party boat was CANCELLED. I called a representative, the Rep. Couldn't tell me the reason, but gave me the number to the actual party boat. When I called I was told that the time slot was taken and was reserved for a private party. I don't know why it wasn't blocked when I was booking. Totally ruined my friends Bachelorette party/experience. I was embarrassed. I will never trust nor use Viator again. I also have told my family and Friends and they too won't ever use this method for booking