Small Boats, Crete Island
We had a great cruise with Diogenes of the Zeus Casual Cruises. This is definitely not for people who get seasick, at least in the Cyclades and Dodecanese.
We love the waves, but the ships have strict restrictions for travelling when the waves are high (see beaufort scale). The smaller the boat, the smaller the waves that are allowed. So one night we just turned back to port instead of getting to our next destination.