Katie and Nan loved their new twin sisters, but they were worried that there would be no cruise on their converted shipping boat, the Dunken, that summer. At last, however, the day came when, fitted in as comfortably as six people could be in such close quarters, they set out for a trip among the islands off the Swedish coast.

A good deal of the time was filled with fishing, swimming, and visiting friends in their summer homes. Sometimes the Dunken misbehaved, as on the day when the smokestack caught fire; more often it was Katie or Nan who misbehaved, but then there were the really perfect times that the whole family would remember forever. The summer had to end, but Katie and Nan wished it never would.

Filled with the sights and sounds of the sea and boats and with the same mischievous humor and good sense that characterized the author's first book,  Katie and Nan, this is the delightful story of a happy family summer.

From the dust jacket