If nobody in your party is tied to a school calendar, book the Mediterranean in September. If somebody is, the first week of September is still worth a hard look. The sea is at its warmest, the August crowds have gone home, and the light in Italy and Greece is at its most forgiving for a long lunch.
What changes after the August bank holiday
Ports that were shoulder-to-shoulder in the first week of August are pleasant again by the second week of September. Private guides are easier to secure. Hotels before and after the ship drop their peak rates. The ships themselves are quieter and skew back towards couples and grandparents, which many families with older children prefer.
The ships we would look at
Silversea and Seabourn come into their own in September: adult, calm, and sailing itineraries with the smaller ports that larger ships cannot reach. Explora Journeys keeps a family-friendly feel for parties with children who have not yet started school or who are travelling in the first week. The Ritz-Carlton Yacht Collection and Ponant suit couples who want the yacht scale and a Riviera or Adriatic routing.
Where we would go
The Adriatic from Venice down to Dubrovnik and across to the Greek Islands. The Western Mediterranean around Corsica, Sardinia and the Amalfi coast. Both still swim well into October. We would leave the Eastern Mediterranean's hottest ports for autumn departures and keep sea days to a minimum.
The catch
September is not a secret. The best suites on the best ships are often held by regular guests from the previous year, so a September sailing still needs six to nine months of lead time for the cabins we would want. If you are set on a particular ship, tell us before Christmas.
What we do
Tell us who is travelling and whether anyone is tied to term dates. We will come back with the two or three September sailings we would actually book, the cabins we would hold, and a pre-cruise night in the embarkation city so the holiday starts a day early.
