The taxi suggestion is a good idea, however there is another way, but its a bit of a hike. We took the La Plage morning walking tour [Tuesday morning?] and went from L Plage to Simpson Bay and back
You walk past Sunset Beach bar, up through Beacon Hill til you come to the villa's overlooking towards P'burg. There are steps down to Simpson Bay just before, you come down near where the Tahoma was. Come to think of it, we then walked back through Beacon Hill, past the AAA building back to Sunset Bar.
I bet if you checked at the La Plage activity desk you could find out about the morning walk - Maho might even have the equivalent - it would "show you the way"!
J&B
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