Had a quick look.some old material.If you try to moor up on the south key in Patras ,You will quickly be moved to the centre Pier if you are over 15m and to the marina at the north if under. The marina has been configured differently to the Sketch .The visitors Pier is at the South end of Marina First in to Starboard ( a Bit rolly in anything more than 4) and a bit smelly.(my long term berth costs about £550 without Electricity Rival31)
Preveza has the ferry berthing moved and where it says shops is full in the season with stern to moorings.. Right in the town centre. a lovely place at the right time, a lot better than Poole.
Levkas has the new marina 50%complete so the congestion on the town Quay has eased.Quite expensive for Greece .but A year at about £1200 + vat for ten Metres
(Day rates are much more)