It shall be unlawful for any person to swim in any area designated as a non-swimming area, or more than 200 feet from the shore, or outside the boundaries of a marked swimming area, or in a location or in such a manner as to create a hazardous or dangerous condition to the swimmer or any other person or object; provided, however, the provisions of this section shall not be construed to limit skin diving when areas for such activity are properly marked. (§ 20, Ord. 360)