The island of St. Maarten/St. Martin is a duty-free port and as such, there are no restrictions on what you may bring with you.
This is one of the major reasons why the island is particularly attractive to yachtsmen. Parts and equipment can be purchased locally at prices that in many cases are lower than the equivalent in the USA or Europe. If an item is not available it can be readily air freighted to the island in a matter of hours without incurring delays or additional costs due to restrictive regulations or customs duty. Naturally, prohibited goods such as drugs, firearms and explosives may not be freely imported and should be declared when clearing in. Failure to do so could result in very serious and unpleasant consequences.