It depends... there are too many factors to consider without knowing what you plan on doing, where you’ll be staying, i.e. what’s available to you for free in the form of amenities, and your tolerance for inconvenience should they NOT be available. Confirm that you are staying on the Dutch side-St. Maarten vs. the French side-St. Martin, since you don’t need a voltage converter on the Dutch side, you do on the French. If you plan on taking any 3 prong electronics, grab a 3 to 2 plug adapter. This adapter is very handy since it allows you to expand your charging capabilities.
http://www.rei.com/product/882476/rei-mini-travel-surge-protector-with-dual-usb-ports-2014-closeoutHere are some destination specific links about packing, weather, and things to do:
http://caribya.com/st.martin/packing/http://caribya.com/st.martin/weather/december/http://www.caribbeanmedstudent.com/2010/05/affordably-fun-things-to-do-in-st-maarten/Exercises to get you packing:
For each day and time of day, visualize what you will be doing and what you are wearing-and write it down. Now pack those things into your bags. Do they fit? If yes, good job, if not start removing duplicate items.
Pick neutral colors—brown, black and khaki—especially for pants and shorts. These colors coordinate well with everything, so you can pack less. Convertible pants to shorts are great. Recommend wearing khaki /navy, slacks/chinos and nice collared shirt on plane so you don’t have to pack it and you have something to wear in case you want to any “fine dining’. Topsiders or loafers as well.
Once packed, grab your stuff and head to the door. Take a “practice” walk around the block and determine if you’ll be able to walk around comfortably at the airports. If not pare it down some more.
Tips for light clothing and drying:
The key to packing light is the ability to wash and dry your clothing quickly. Many people talk about "quick dry" and those TM items get very expensive. Instead look for items that "dry quickly" such as Nylon and polyester. The higher the content the better! Most performance fabrics are made primarily of these synthetics. Avoid cotton as much as possible or go with blends. I personally love pockets, I can never have too many!
Pack concentrated laundry detergent (3oz), and 550 paracord to make a clothesline (and other uses). Many hotels have clotheslines in the shower but there isn’t always sufficient air circulation/sunlight to dry your clothes compared to outside or main room.
After hand wringing clothes, shake them out, then, roll them up in a dry towel and wring the towel tightly. It will absorb much more of the water and speed drying time on the clothesline. Hopefully you’ll be in a hotel that provides you a few towels and exchanges them. If not you’ll need to dry out the towel, but that should have more time to dry before the next use vs. the clothing.
If you’ll have access to a hair dryer, this Vapper seems interesting. Although, being a new Mustachian, I thought about trying a DIY method with a heavy duty trash bag and rubber bands!
Other misc. ( Yes, you can get these things there, but they’ll be much more expensive)
Ziplock bags-come in handy to organize stuff, and of course for snacks/lunches/spices/sugar/coffee.Collapsible soft side cooler for beach use; Hat, Sunglasses.