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.
The only safe haven on Agsitri, but wins no beauty prizes. The lush and green island is attractive. Beware of the rocks and sand bar between it and Aegina, well marked in the pilot books and charts, but otherwise not at all obvious.