River cruising is the rare product where the brochure undersells the experience. The ship is small enough to dock in the middle of town, so there are no tenders, no ports an hour from anything, and no sea days. You walk off the boat and you are in Cologne, or Strasbourg, or a wine village whose name you will mispronounce all week.

The Rhine gorge between Koblenz and Ruedesheim is the stretch everyone remembers: forty castles in two hours, best watched from the top deck with coffee. Spring departures add the tulip fields near Amsterdam at their April peak, which is a genuinely once-a-year sight.

Cabins are compact, so pack light. And if you are choosing between a room with a balcony and one deck higher without, take the higher deck; on a river, the whole ship is a balcony.