Worth it for the illustrations alone, which are completely adorable (but if you know Vernon, that comes as no surprise). The text is occasionally a little info-dumpy for an adult reader--very "here is a list of cool facts about the ocean, kids! isn't science neat?"--but since the intended audience is, in fact, kids, I can't really hold that against it. I doubt it would have bothered me when I was eight, anyway.
The potato salad subplot is probably my favorite part.