after 9pm, you goto jail for sleeping on the beach. 

Sec. 5-4. Sleeping on public beach after 9:00 p.m. prohibited. It shall be unlawful for any person to sleep on the beach within the city between the hours of 9:00 p.m. and sunrise. (Code 1980, § 7-10-4)

It is unlawful for you to change your clothes at a gas station without getting the gas station owner’s permission in Myrtle Beach, South Carolina.

Sec. 5-13. Changing clothes in public lavatories, etc. It shall be unlawful for any person to undress or to put on a bathing suit, change from a bathing suit to normal clothes or change from normal clothes to a bathing suit in any public lavatory or toilet room in the city without obtaining permission or consent from the owner or proprietor. (Code 1980, § 7-10-13)

In the coastal town of Myrtle Beach, it is illegal to piss in the waters of any park.

Sec. 14-139. Prohibited acts in parks and other public facilities. It shall be unlawful for any person using the public parks, recreation areas, grounds or facilities of the city (referred to in this article as parks), specifically to include Chapin Memorial Library, to either perform or allow the performances of any of the following actions or conduct, unless such action or conduct is authorized, permitted or supervised by the cultural and leisure services department director or his designee. (2) Unlawful to pollute waters. Pollute waters means to willfully or negligently throw, discharge or otherwise place or cause to be placed in the waters of any fountain, pond, lake, stream, bay or other body of water in or adjacent to any park or tributary, stream, storm sewer or drain flowing into such waters any substance, matter or things, liquid or solid, which will or may result in the pollution of such waters. (Ord. No. 2000-42, 8-22-00)