Board a typical picket boat for a traditional caldera tour, end for swims, stopover at the volcano
https://daniela-perego.com/santorini-famous-sights-tour-o-apolytos-odigos-gia-ta-pio-emvlimatika/
Board a ordinary wood boat for a conventional caldera tour, stop for swims, stopover at the volcano, and savour onboard reviews and snacks.