We are going to in Athens in May 18 and plan on leaving Athens to go to Paros on May 22 (Friday). We want to take a "fast" ferry. However, we do not understand all the different options (economy, seating, pricing, fast vs slow, etc.) Would someone please explain how the system works. Do we book through an agency (we have "Greek Travel" as a possibility)? We have the web site www.greekferries.gr to kind of help us. We also want to leave Paros for Naxos on May25 (slower or fast ferry) and later leave Naxos for Santorini (slower or fast ferry)on May27. We will fly back to Athens from Santorini later, and will not need a ferry. We would appreciate any an all suggestions/ideas/explanations on the How to, etc. of booking, selecting, etc. Please, please help us.