St. Martin was safe at night. Not much petty crime. Nobody trying to sell you pot or asking for money. Water is safe because they have to purify it (it's closer to a desert island). Great French restaurants on the French side. Gambling, inexpensive alcohol on the Dutch side. Takes only 30 minutes to get from one side of the island to the other. Probably takes Canadian currency without having to go to an exchange.
Speaking of clothes and flippers. I forgot to pack my swimsuit and sandals the first time we went. But hardly needed them because our hotel was at the north end of a clothing-optional beach.