Hello captain ... SXM has something like 34 or 36 beaches and I would say I've been to maybe half of them. But, this is a really hard question to answer because conditions can change from one-day-to-another on island beaches such as these. But, on average the beaches that always seemed to generate stronger waves on a more consistent basis were Orient, Dawn, Mullet, Cupecoy, Maho, and I suppose Simpson Bay (but, I have seen Simpson calm from time-to-time). The calmer beaches with less wave action other than Le Galion definitely were Great Bay Beach and Little Bay Beach near Philipsburg. Anse Marcel, Grand Case, Happy Bay and Friar's Bay on French St. Martin are probably somewhere in between. These are just my experiences.
Here's a website that might help. You can at least read the brief write-ups about each beach: stmartinisland.org. This website comes up if you do a Google search for "the beaches of St. Martin." One nice thing about St. Martin is that if you have a rental car and conditions at one beach are not ideal, just hop back in and the next beach is just 10 minutes away!
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