Pamlico Sound is a large estuarine lagoon in North Carolina. The largest lagoon along the North American East Coast, it extends 80 mi long and 15 to 20 miles wide. It is part of a large, interconnected network of similar lagoons that includes Albemarle Sound, Currituck Sound, Croatan Sound, Roanoke Sound, Pamlico Sound, Bogue Sound, Back Sound, and C…Pamlico Sound is a large estuarine lagoon in North Carolina. The largest lagoon along the North American East Coast, it extends 80 mi long and 15 to 20 miles wide. It is part of a large, interconnected network of similar lagoons that includes Albemarle Sound, Currituck Sound, Croatan Sound, Roanoke Sound, Pamlico Sound, Bogue Sound, Back Sound, and Core Sound known collectively as the Albemarle-Pamlico sound system. With over 3,000 sq. mi. of open water the combined estuary is second only in size to 4,479 sq mi Chesapeake Bay in the United States.