(a) Commercial structures constructed prior to June 17, 1992 of any size or use are not exempt under this Part, and must apply for a lease, easement, permit or lesser interest in State-owned lands underwater. However, the following structures shall be exempt from the requirements of this Part:

1. (1) existing noncommercial structure constructed by or on behalf of the owner prior to June 17, 1992, containing a surface area (outermost perimeter) less than 5,000 square feet or less and if a docking facility has a capacity of seven or fewer boats up to 30 feet in length;
2. (2) any water dependent structure constructed after June 17, 1992 containing a surface area (outermost perimeter) of less than 4,000 square feet and not exceeding 15 feet in height (above mean high water) and, if a docking facility, has the capacity for five or fewer boats up to 30 feet in length and if a mooring facility has a capacity of fewer than 10 boats up to 30 feet in length;
3. (3) the relocation or reconfiguration within the described perimeter of the dock, piles, ramps and like structures authorized by lease, easement, permit or lesser interest provided such relocation or reconfiguration does not interfere with the riparian or littoral rights of adjacent upland owners; and
4. (4) nothing in these regulations shall be construed to mean that structures below the thresholds constitute a valid and reasonable exercise of riparian or littoral rights.