You could also consider St. Barth's for a day trip. I'm not encouraging this in any way because I'm all for keeping vacation dollars (and euros) on SXM, but if you've never seen St. Barth's it is really beautiful. Or, a least it was prior to Irma. But, as I've posted on this board before it's just big time expensive. But, the beaches their are lovely and even the most popular one (St. Jean Beach) only gets crowded on the weekends. The two clothing optional beaches that face south (Gouverneur and Anse de Grande Saline) allow you to enjoy the beach with as little or as much attire as you desire without a ton of people around, and that's something not permitted on Anguilla. But, you will need a rental car if you plan to explore the island beyond the port city of Gustavia. Just another option to ponder.