Well, the lads and I had some beach time today, and it brought this one to mind: "Green Smoke," by Rosemary Manning (1957, repr. Jane Nissen 2008, ~150 pp), a perfect beach story! (Enjoy summer while you can...)

A little girl named Susan is on a beach holiday in Cornwall; in a secret cove, she discovers a lovely creature, R. Dragon by name, who is 1500 years old. (In fact, he lived for a time at the court of King Arthur, a fact which interests Susan very much.) R. Dragon was tamed by St Petroc; he has no teeth, and has very nice manners, so he is not in the least frightening. He is vain, though, and rather greedy (he's very fond of Susan's biscuits and almond buns), but mainly he is full of interesting stories. He also takes Susan on some very exciting adventures, including tea with a mermaid. There are charming drawings by Constance Marshall. It's a book full of jokes and fun--just right for summer!