I think you COULD do it, but not sure why you would want to. It would be pretty expensive. The last I knew, Liat does that route, but I have no idea whether the timing would lend itself to a same day return or not. I would say not. Better to spend at least a few days there, if you want to go. There are several islands there and they are all different. AA now has a non-stop from Tortola to Miami. So, your best bet for a combined trip might be a one way to SXM, a few days there, flight to Tortola, a few days there and one way from Tortola to Miami.
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