At Passau, on a blustery day, the Donauprinzessin (Danube Princess) was at its mooring. Napoleon wrote of Passau that "in all of Germany I never saw a town more beautiful", and the tumble of baroque and neo-classical houses proved him right. The Danube Princess herself, while hardly a thing of beauty, was easy enough on the eye, a gleaming white floating hotel with 200 passengers. We prepared to navigate the Danube in suitably leisurely style. River cruises, like rivers themselves, move slowly.