The tides explained for kids! Ralf, the frog, is on vacation at the North Sea. He falls asleep in a beach chair, and when he wakes up, he is astonished to find that the North Sea is no longer there. He sets off to the mudflats to get to the bottom of the matter. Along the way, he has a bit of a rough encounter with the little beach crab Klara, who, despite some bickering, can tell him a lot about ebb and flow. This cheekily illustrated children's book explains the mystery of the tides in an entertaining and easily understandable way. Why is the water at the North Sea sometimes there and sometimes gone? What does the moon have to do with it? And what role do the ocean's water masses play in this? With this amusing book, not only does the frog Ralf find answers to many questions!.