I know in St Maartin it is Phillipsburg on the Dutch Side and in St Thomas it is Charlotte Amalie. You may want to try www.dcltribute.com for longitudes and latitudes.
At St. Maarten, the Magic docks at the Great Bay Port (www.greatbay-port.an) at Philipsburg. The dock is at the southeast end of Great Bay on the south side of the island. The approximate coordinates are 18.01°N, 63.05°W.
At St. Thomas, the Magic docks at the West India Company dock at Havensight, which is at the east end of Charlotte Amalie Harbor on the south side of the island. The approximate coordinates are 18.34°N, 64.94°W.
I can't help you with maps that show the coordinates, but here are some decent maps for St. Maarten...
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