USACE Federal Navigation Channel GIS

The Department shall make maps and other information available on its website to assist landowners in identifying whether their property is adjacent to a federal navigation channel.

Per, CAMA (113A-118(g)): 

(g)           For fixed docks, floating docks, fixed piers, floating piers, or walkways damaged or destroyed by natural elements, fire, or normal deterioration, activity to rebuild the dock, pier, or walkway to its pre‑damage condition shall be considered repair of the structure, and shall not require a permit under this Article or rules adopted thereunder, without regard to the percentage of framing and structural components required to be rebuilt. At the time a dock, pier, or walkway damaged or destroyed by natural elements, fire, or normal deterioration is repaired, the width and length of the dock, pier, or walkway structure may be enlarged by not more than 5 feet or five percent (5%), whichever is less, and the structure may be heightened, without need for a permit. The owner shall, however, be required to comply with all other applicable State and federal laws. The provisions of this subsection shall not apply to docks and piers (i) greater than 6 feet in width, (ii) greater than 800 square feet of platform area, or (iii) that are adjacent to a federal navigation channel. 

USACE maps link for identifying whether your property is adjacent to Federal Navigation Channel: NC Federal Channel Adjacency