Dorothy and Dick have an adventure in the English countryside, involving frantic chases, calamitous boat collisions, and the attempts of their friends to protect nesting birds from rude holiday boaters.

While on vacation in East Anglia, four children, whose previous sailing experience is limited to dinghies, accidentally drift out to the North Sea after the rising tide causes their cutter to drag anchor.

Follows the adventures of two groups of children who spend a winter holiday by a great lake next to the mountains.