Barrier Islands – Cape Hatteras, NC. Check and double-click the Problem 7 placemark to fly to Cape Hatteras off the coast of North Carolina. Use the Hand tool to determine the range of heights for the sand ridge specified by the placemark (presumably this sand ridge would provide protection from waves of this height or lower for areas on the lagoon side of the ridge). Choose one: 0–1 m 3–12 m 15–25 m