Answer:No , S(he) is not liable to prosecution for indecent exposure
Explanation:What is indecent exposure? Indecent exposure refers to an act of exposing your whole body or part of your body in public where this exposure considered morally wrong or socially unacceptable in that local area .
Indecent exposure differs from state to state based on what laws of that society and community consider to be indecent exposure.
This may be based on religious morals and standards ,tradition or just what society consider as a norm in maintaining social order.
When someone is at the beach it is expected that they are likely to be half naked or in some cases even fully naked , so sunbathing at the beach is expected and can't be an insult to the public .