Need Advice on Checking into St. Martin from BVI

[RRMontgo]

Greetings,
We will be making our first passage from the BVI to St. Martin this weekend. I'm reading on Noonsite about the difference in check-in procedures between the French and Dutch sides. It appears to cost less to check into the French side first, enter the Lagoon through their bridge. If we go to the Dutch side of the Lagoon to visit Island Water World and Budget Marine, do we have to check in on the Dutch side? We will eventually spend time on the Dutch side, including Simpson Bay anchorage and around to Oyster Bay. When do we need to check into the Dutch side? Bottom line, what's the best way to check into French and Dutch St. Martin from the BVI?

Thanks!

Rob & Regina
SV Ramble On