The volcano of Santorini makes the sea around it very interesting. A boat can take you to see the caldera and its hot springs, as well as the surrounding islands, such as Thirassia. With a lot of sunscreen and good company, this could be a trip to remember, whether you prefer a sailboat or something more modern. If you’re an experienced scuba diver, then Santorini can offer you even more thrills, as the sea bottom, due to the volcanic eruptions, hides caves and cliffs and shipwrecks.