Also when sun-bathing on the beach on proper clothing should be paid attention on.
Thais are in as far as nakedness is concerned rather prude compared with us Westerns. When observing Thais, mainly women, going for a swim you will recognise that they are often wearing shirt and trousers when going into the water.
String-thongs are frowned upon both for women and for men. But swim-trunks covering the bum of a man are sufficient.
Women whereas should by no means lie about topless or even totally bare!
By this extremely disrespectful behaviour you can quickly lose your face what in turn can lead to not being respected there anymore during your Thailand stay.
If you go in between to the beach restaurant a bath towel or a Sarong should be looped around the hips.