Friendship, resourcefulness, and sailing, too Arthur Ransome's Swallows and Amazons series has stood the test of time. More than just great stories, each one celebrates independence and initiative with a colorful, large cast of characters.
In The Big Six, trouble is brewing for Joe, Bill, and Pete, the three boatbuilders' sons who (more or less) live full-time aboard the Death and Glory and the three Coots, Tom, Dorothea and Dick. The problem seems to be that boats are constantly being set adrift, and all the evidence points squarely at the three Death and Glories. In a clever bit of detective work, and with some help from a sophisticated photographic trap, the six manage to exonerate themselves and catch the villains.
Of course, this book, like all Ransome titles, is about a lot more than clever detective work; it has the smell of water and tarred rope, the sound of birds, and the plight of children left to their own devices and coping with everything from catching monster pike to trapping midnight eels.
The entire Swallows and Amazons series is for children or grownups, anyone captivated by a world of adventure and imagination, exploring and setting sail.