old children's book about children's small boat adventure

I read only the beginning of this chapter book in the 1970's but didn't get to finish it. It was not new then - maybe 20 years old or more. The children in the story take a small boat (a canoe?) on several trips on a misty river where there are swamps and islands. I believe the title may even contain words like rivers or islands or both. Each trip they make they spend time creating a map of the river area. I think there is also a part of the story where the children fill up a bathroom sink with water and put some things in it (very small river animals?). The story may have taken place in a British colony in China or India. The main character may have been the child of a British Officer or Official stationed in some exotic place in a British Colonial style home. Your assistance would be appreciated.

There are quite a few books about children in small boats. One that I can think of that partly fits your description is The River at Green Knowe by Lucy M. Boston. Three children in a canoe explore a river full of mysterious islands. They draw a map and add to it after each day's adventure. Although the story takes place in England, the children are international: one is from China, and another from Poland. The illustrations are very misty looking.

Thank you very much SylviaC! It appears that you are correct and, apparently, the local library has a couple of books from this series. I look forward to checking them out. ~R

I'm glad I could help. It is a lovely series, but the plots and characters can vary greatly in the different books. Some of them are light fantasy, one has no fantasy, and one has witchcraft. I enjoyed them all, but some more than others.

Wow. I love the Green Knowe series, and I know I read River, but I would never have guessed it from your description. I guess it's time for a reread!