There is established a no wake zone to begin one hundred yards in a southwesterly direction upriver of the Kiawah Docking Facility and extending to a point one hundred yards in a northeasterly direction downriver of the facility. These boundaries must be clearly marked with signs. Expenses for the establishment and maintenance of signs in the area must be borne by the owners of the Kiawah Island Docking Facility. The signs must be designed and installed as specified by the department.