THE RIDDLE OF THE SANDS

When Carruthers joins his frien Arthur Davies on his yacht Dulcibella, he is expecting a pleasant sailing holiday in the Baltic Sea. But the holiday turns into an adventure of a different kind. He and Davies soon find themselves sailing in the stormy waters of the North Sea, exploring the channels and sand banks around the German Frisian Islands, and looking for a secret - a secret that could mean great danger for England.