North Carolina Wildlife Resources Commission
The North Carolina Wildlife Resources Commission issues fishing licenses (both saltwater and freshwater), handles boat registrations, enforcement of North Carolina boating rules and laws and regulations for inland freshwater size and bag limits. But their jurisdiction also covers most of the sounds. Some people refer to them as the game wardens. If you are stopped by them, they will generally be checking to see if you and all parties fishing have valid fishing licenses and they’ll check your catch to make sure it is legal. If you’re in a boat, they’ll also check your boat registration, safety equipment (Personal flotation devices 1 per person, throwable cushion or life ring, fire extinguisher, child life jackets), and if driver has been drinking. As long as you stay within the inlets, freshwater boating regulations generally apply.
North Carolina Marine Patrol
The North Carolina Marine Patrol enforces the commercial fishing industry but they also enforce the law for recreational fishermen regarding licensing, boating and size/catch limits in saltwater areas. Their jurisdiction is all coastal waters and up to three miles offshore. Note that beyond three miles in the ocean federal laws apply. Note: the line between saltwater and freshwater can be fuzzy around here particularly on the northern Outer Banks.
US Coast Guard
The US Coast Guard can stop you on any navigable water. Generally they have bigger fish to fry than recreational fishermen, however, they can stop you. They are mostly interested in keeping you safe but can also check your catch.
Coastal Angling Program
When you return to the dock, you may be stopped by a person taking a survey about what you caught. This is to help the NC Division of Marine Fisheries collect data about species caught for fisheries management, etc. These folks are volunteers and nice folks but they have no legal authority so you are not required to answer their questions or allow them to look in your cooler. Their survey results feed a weekly fishing report for what is being caught in the area.