Much of the Greek charter fleet is based in the area mostly at Alimos marina (Kalamaki)
Flights to and from Athens are numerous and good value. Getting to the departure marina is easy and quick.
Enormous selection of charter yachts
Two attractive itineraries for a one week cruise
You must cross shipping channel at start and finish (tiresome)
Crowded with other charterers less competent than you!
They are 6 night/7 day itineraries that with thought can be combined into 14 day cruises. If you have that long, consider the Southern Itinerary and continue south down the quieter East Coast of the Peloponnese.
Major charter base. Scruffy but all services available. Avoid at weekends. Neither their web site nor their pricing informaion has been updated since 2007! You would only go there as a private yacht owner to get something repaired. No email address available.