Layers. The weather on the island changes throughout the day. It is not unusual to have a 20-30 degree temperature fluxtuation in a 12 hour period. If you are planning activities on the water, be prepared for temps that are at least 10 degrees cooler than on land. A rain slicker or wind breaker as well as waterproof pants for kayaking will come in handy. Sunglasses, sun screen, and of course a camera are also a must. Many of the locals always carry a camera because you will never know when you see the perfect picture.