Pack LOTS of swimsuits you pretty much live in them! Pack some afterbite and maybe benadryl!! A small beach bag to take all your things down to the beach for the day. Take some small bills you dont tip at the resort but you do tip on the Cat cruise, the music guys on the beach. Also if you go off the resort to shop it is easier if they do not have to make change for you! Water camera? Maybe a small wrap for feathers it can get chilly in there. Advil and tylanol. I take tums also!! A pen for filling out the customs forms on the plane. I take large zip lock bags, the super size ones to pack up the damp swim wear and sandy flip flops for the way home. I also put any rum we buy in them in case it breaks in the suitcase!
Bug spray w/ plenty of Deet in it, q-tips, tyelenol, immodium/pepto (just in case, never know how tummy will react to all the alcohol/food). I bring Benadryl because I tend to be allergic to everything (sensitive skin). I suggest locking your wedding bands and things in the safe as soon as you arrive. Many ppl have lost their wedding rings in the ocean. you will NEED bathing suits, 2 outfits you can mix n match for dinner at restaurants requiring proper attire.
A hat for the Bride with a wide brim to protect her beautiful face
As for sunscreen I recommend a really good SPF for the face/ears/top of feet. I used Neutrogena 100SPF for face this year. It was the first time in 20 trips I did not come back with a red nose and burnt cheeks.
If either of you plan on doing braids a hat or a spay on sunscreen. A burnt scalp HURTS and can ruin a vacation!! A T-Shirt you don't mind getting wet while snorkeling, the sun will reflect off the water & burn you quickly.
Bendy Straws for your drinks. I think I saw someone post a while ago, you don't want to have to sit up to take a drink while enjoying the wonderful red flag service on the beach....the whole point is to maximize the relaxation factor! Enjoy!