We Didn't Mean to Go to Sea

After a gentle start (there are seven chapters of preparation before anything out of the ordinary happens), this turns into an exciting story, in which four children find themselves unintentionally sailing a yacht across the North Sea, at night and in bad weather.

There are no baddies in this story: its heroes battle against the elements and their own limitations. But it's quite an epic struggle in which they're at real risk of death.

Readers should be warned that this is a sea story written by a sailing enthusiast: non-sailors may find that the blow-by-blow account tells them more than they wanted to know about sailing.

Also note before reading that it dates from 1937, so it's somewhat old-fashioned in general. The world before the Second World War was significantly different from the world we know now.

A story like this couldn't plausibly be set in modern times, because at least two of the children would have mobile phones, which would wreck the whole plot.