The book has some advice about rivers which NB's seem to ignore, moor facing upstream etc... but the film doesn't mention
rivers, although I only quickly skimmed through it.
It's an old book, re-issued perhaps, rather than new I think?
I agree, mostly seems aimed at NBs, but still quite a useful guide for complete river newcomers or boating beginners. I wonder if copies will be left on all hire boats? <that's not a serious question,of course!>