They send a box about a month in advance. For our Danube River cruise, it had lots of things (an ipad cover, backpack, luggage straps, etc) plus a folder with a small book about the Danube area, as well a helpful a spiral book with information including the daily itinerary. In the center of
that was a chart with the excursion options so we could plan those in which we would participate. We had a pre night in Budapest and in the morning at the hotel there was a meet and greet with one of the adventure guides, who took our preferences down. I believe that night at dinner they caught up with those passengers who hadn't filled out preferences yet. This gives them a general idea for numbers. One night we skipped the afternoon excursion and a bus and an Adventure Guide (Stephanie) came back to the port for DH, myself and one other Adventurer. They really are pretty flexible if you change your mind-or at least they were on our Danube Holiday trip