Luggage and bags:
A carryon or a suitcase will do depending on how long your trip.
Clothing/Shoes/Weather Gear: Light comfortable clothing such as shorts, tee shirts, sundresses are good to keep you cool. A hat is also a good idea to keep your head and face from getting sunburned. Comfortable shoes for walking and flip flops for the beach.
Toiletries and Medical Supplies: Shampoo, conditioner, lotion, razor, shaving cream, deodorant, toothbrush, tooth paste, bodywash, sunscreen, contacts.
Photo Equipment: Digital camera, memory card reader, video camera
Camping/Beach/Outdoor Gear: bathingsuits, towels, flip flops
Luggage and bags:
A suitcase or a backpack whatever you like, its staying at your hotel anyway.
Take a daypack for your beach and swimming wear.
Clothing/Shoes/Weather Gear: Light linnen clothes. Jeans. Sandals. Flipflops. Beachwear. Everything you like in a warm humid climate. (People in St. Maarten dress whatever they like, sporty, classy etc.)
Bring some nice clothes for going out.
Toiletries and Medical Supplies: Just your usual toiletries. But you can buy everything there at the supermarkets also so no need to bring everything along.
But buy a good mosquito repellent !
Or buy a "anti bite" at the local drug store.
I myself didnt use a mosquito repellent (it smells !) So I just let the mosquitos bite and immediately put some "anti bite" I bought there at the local drugstore on it and I didnt have a rash or big bumps at all ! So that worked better for me.
Photo Equipment: You can buy everything there its just a little bit more expensive than at home maybe.
I even develloped my photofilms there ! (I couldnt wait to come home) Thats also good and they charge you normally. (The photoshop at backstreet)