Germany: Duhnen mudflats A mixed racecard (also featuring trotters) is held annually in July on what is effectively the seabed at Duhnen, a North Sea resort on the outskirts of the port city of Cuxhaven. Set against the dramatic backdrop of the Elbe estuary, an international shipping lane, the racing surface is exposed by the ebbing tide. About 30,000 spectators attend, watching from the nearby dyke.