Naturally or lawfully altered shorelines and development rights on piers

A zoning district boundary line which intersects the shoreline lawfully existing on November 13, 1981, shall be prolongated, in a straight line, to such naturally or lawfully altered shoreline. Lawfully approved piers or other lawfully approved structural extensions of the shoreline, as may be so altered, shall not generate development rights; however, uses accessory to the principal upland permitted use, except for off-street parking, shall be permitted.