When we visited Greece in the summer we stayed for part of the trip at Ekies. It was the perfect resort to base our boat trips from. The small beach line in front of the hotel is littered with boat rental companies, from which you can rent a boat for a full or half day and explore the surrounding islands. I haven't done this since I was a teenager and younger, it was blissful. The sea is perfection and being alone together on the boat all day, heavenly, stopping only for lunch at a restaurant reached from the beach with the boat. I cant recommend it enough if you've never done it. Summer magic.