I was a little scared when I started to read this book, because I thought it was going to be like "The Lord of The Flies" - and I didn't have much of a good experience with that book.
"The Lord of The Flies" represents the possibility of savage behaviours in let-alone-kids. It shows that when we [human beings] are in critical situations, like wars or cases where there is no leaders or something like that, we become very wild and disrespectful.
"Sand Captains" - or "Capitães da Areia", in portuguese - is the portrait of the kids that run in the streets of Salvador da Bahia or any other city in Brazil. I have never been to Brazil, but I know it is just not paradisiacal landscapes and forests and all that. In Rio and São Paulo, for instance, I know that there are loads of favelas where kids live in poor accommodations, with very poor education and (some) with no money at all - some maybe don't even have that privilege [to have education]. This book also shows us that when we want - even if we have no money or conditions -, we can find opportunities out there to get better in life.