WHY: a friend said of the pacific NW guide, "The landslide winner on the ease-of-use-meets-comprehensive information front was Beachcomber’s Guide to Seashore Life in the Pacific Northwest (Revised). It had every a photo of every single creature we found, along with just enough hard science to satisfy the boy’s curiosity." While we live in the NW, we travel frequently to California, so I think we'd best have this one too.