Saint Helena Sound is a coastal inlet in the Lowcountry region South Carolina, located along the Atlantic Ocean between Beaufort and Colleton counties. Located within the relatively undeveloped ACE Basin, the sound consists of the mouths of the Ashepoo, Combahee, and the south branch of the Edisto rivers, of which the ACE moniker derives from. The inlet is located 15-mile (24 km)east of Beaufort, between Edisto Island and Hunting Island. At its widest point, Saint Helena Sound is 7.5-mile (12.1 km) across. The Intracoastal Waterway crosses the sound. Much of lands surrounding St. Helena Sound has been preserved through the St.