You might find that trying to understand the local aviation laws and who governs what in St Martin/Saint Maarten are more effort than a weeks holiday are worth! I was there for four months and still never managed to get my head fully around who was in charge!
You might be able to get a fixed wing tour but I don't think there are any helis based on the island any longer.
Hope you enjoy your holiday and make sure you visit 'the soggy dollar bar' most enlighting.