We booked the day before at the booth near the coach stop from Trapani, leaving €20 deposit and cellphone contact number. We arrived at the boat the following day to find it deserted. We went back to the booth which was unmanned. The main office was closed, as it is every day at departure time, even when there is no departure! There were no notices posted anywhere explaining why the boat was not leaving. The phone was not answered. We went back to the pier and managed to join another boat run by another operator. After returning in the evening we went again to the booth and saw a man who said he was the owner. Big guy with long bleached hair. We complained and were told it had been cancelled due to weather (despite the other operators running, and that the weather had been excellent on our excursion). He claimed the had tried to call me but somehow couldn't get through (unlike everyone else who called us on holiday). They didn't leave a notice at the boat or rebook us on another operator's boat. Why? I can only assume they don't really care. The "owner" yelled at us and eventually gave us our deposit back. If you want to waste your time and have bad memories if San vito, book this tour. If not, try Hippocampus instead, but book early because they fill up quickly.