The route reversed
The adventurers are relieved to have survived the sea crossing intact. Hans repairs the raft so it will be ready when they wish to go back. In the meantime, Harry and the Professor walk off along the shore in search of a supply of fresh water, the only provision they do not still have in abundance.
On the way, the pair calculate how far they have come and how far they still have to go before reaching their destination. At one point, the Professor consults the compass and is momentarily confused by what it reads. He shakes it, reads it again and gives a violent start. The Professor is stupified and Harry rushes over in alarm. He looks at the compass himself and a loud cry of surprise escapes his lips. It points to the shore and not out to sea. Disappointment floods through him as he realises that the wind must have changed direction during the storm. They are back on the same shore they left so many days before!
The Professor is crestfallen and then furiously indignant. He is determined to try to cross the Central Sea once more. Harry thinks it is too dangerous and advises retreat, but his uncle will not hear of it. Arguing, they continue to walk along the shore.