We agree with EdB and GaKaye!
Definitely get a rental car, even if you plan not to drive much!
To walk the beach after dark is dangerous and, frankly, not very smart ...especially after the recent demolition work.
With a rental car you can enjoy the restaurants in Grand Case, go shopping in Phillipsburg and/or Marigot, visit the Butterfly Farm in the early morning, and see more of the wonders of St. Martin...even if you spend most of the time on Club O's beach...and do so safely. And as others have said, you will likely pay as much, or more, for taxis to and from the airport plus one or two excursions...
Do yourselves a favor and rent a car!
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