We booked the Day Cruise Catamaran tour of the caldera. The boat tour itself was great! A 3-person crew that was very attentive, friendly, and professional. There were only 3 other parties (9 people total, including us) on the boat with plenty of space for everyone. The lunch on board was very good and freshly prepared including a Greek salad, tomato seafood salad, dolmas, tatziki, choice of chicken, pork chop or grilled vegetables, and Greek yogurt with sour cherries for dessert. Beer, white/red wine and sparkling or still water generously provided. The trip included a stop with swim in the caldera and hot springs (could access them right from the back of the boat), visit to red and white beaches, and lots of scenic coastline. Pick-up at our lodging was on time though the driver was a bit fast, making several passengers nervous. Overall, a great experience and a highlight of our trip to Santorini.