Electricity in St. Maarten (Dutch side) is exactly the same as the United States with a 110 voltage at 50 Hz standard. Standard US plugs and appliances are compatible too. On the other side, St Martin (French side) has a 220 voltage at 60 Hz. French plugs are required. It is highly recommended to bring a transformer plug with you to adapt to any side of the island. Make sure you check what the voltage is before plugging in your electronics if they do not automatically convert the current themselves! Many computer have lost their lives that way…