Ok...found it....here what the SXM Government requires....at least they put it in writing. Enforcement is another issue..

Quote
Wearing a mask is mandatory in all public places, airport, public transportation, supermarkets and in all areas, buildings and stores where social distancing is not possible.Keep a safe distance of 5-6 ft (1.5 – 2 m) at all times, including beach visits.


https://stmaartenehas.com/general-information/

It would be nice to know what the actual practice is though.......