Do I really need a book about seaweed?
I happened to be in Torquay at the weekend and there is some sort of sea safari park along the promenade. You can access the shop attached to it without needing to pay to look at penguins, so, under the vain hope that THERE WOULD BE BOOKS, I went in. And there were!
I ended up buying the rather splendid Seaweeds of Britain and Ireland, a photographic guide that claims to be able to help you confidently identify over 200 species of them. As with most things, there are plenty that do need a microscope to clinch an identification, and I'll leave those well alone. I almost - almost - picked up The Sea Anemones and Corals of Britain and Ireland as well, but thought better of it. I wish I had now. Both are published by Wild Nature Press / Marine Conservation Society / Seasearch and will only cost you £16.95. Not bad for such a well produced book. My natural history book choices are getting more specialised and obscure by the day.