What should we pack?

First of all, what NOT to bring:

PLEASE do NOT bring jewelery or valuables.  

Any type of loose fitting, cool, outdoor clothing, bathing suit and footwear you can stand to ruin should be
packed.  

A knapsack or day pack is a great idea for tours.  In it you can carry your essentials such as camera, film,
sunscreen, insect repellent, sunglasses, etc.  During the day, the sun can become very hot.  Sunglasses,
good sunscreen, and even a brimmed hat are in order.  Bring mostly casual clothes such as short pants,
t-shirts, swim suits, etc.  

Even "formal" restaurants will find a casual tropical outfit very appropriate.  

Sandals and flip flops are quite in order.  If you can bring an additional pair of sneakers / shoes with
threaded soles for hiking that would be great.  

If you are doing mainland tours that require some trekking, bring hiking boots/sneakers which you do not
mind getting wet or muddy will work best.