Whilst the Eastern Mediterranean is accessible with no fly cruises from the UK, these ports are further from the UK than the Western Mediterranean and are normally accessed with flights to Malta, Naples, Majorca or Venice as a starting point. This is a very special area and digs into history and interests of many kinds from mythology, Game of Thrones to the Bible. An evening cruise out of Venice is quite romantic, see film.
Eastern Mediterranean - the help you need is here
Zakynthos is the third largest Greek island in the Ionian sea. It has a walkable town, many churches and the best bays are boat rides away. Tours will include wine making, Anafonitria 15th Century monastery, Volumes for rugs and souvenirs, honey and cheese. Aghia Maina a local village seven miles away and Laganas the islands more commercial holiday resort. See our town guide and film on monastery at the southern end.