Great tips! These are truly valuable tips - as opposed to usual mundane ones. In fact, for anyone who reads this, hears a packing tip. In your carryon, all you need are:
1. Travel documents (top priority).
2. Swim attire, suntan/screen, sunglasses. (just as important).
Anything else is easy enough to get.
Yes, I know some of you out there are saying items #2 are easy to get too, but, if you have them with you you won't miss any valuable sun-time. You can get the other stuff after the sun goes down.