I went to hainan island for vacation last winter. It was very hot There are many places of interest such as tianyahaijiao daxiaodongtian and wuzhizhou island The color of the seas there werevery blue and clear.you cansee many foreiners swimming in the sea,by the way ,youcan enjoy the delicious seafood.the people there were very friendly ,too.I believe you can have a good time if you go there.