A Tahiti Tan will occur sometimes when you don't want it to happen!!!
While in Tahiti last year, during a sea day, my wife sat out on the "balcony" and read for 1/2 the day. She was in the shade. After 1/2 day, she got up and realized that she had burned from the reflection off the ocean. She was 1/2 lobster.
I told her to go out and move the chair around for a full lobster look.
So whatever you choose to do, just remember, that the sun in Tahiti is about two miles away from your skin. AND it will burn!
Have fun, and wear a hat!