We just returned from our trip to Athens and Santorini, and when I asked my teenage daughters what the best part of the trip was, this is it! We spent the day out on the water, snorkeling and swimming, and my daughters were even able to try scuba for the first time. We swam in a cavern, which was awesome, and then visiting a beach, and then another island for snorkeling, before heading off to the Temple of Poseidon for sunset. At each place, we had as much time as we wanted - there was no pressure to get moving to the next spot as you find on larger trips. (one hint - book the afternoon time, as the morning time does have a deadline to get back) George and Nikos are wonderful - its so comfortable to just hang with them on the boat, and they went above and beyond in everything. Don't miss this one!