It basically encompasses the area along the eastern shore of Puget Sound between the Shipwreck (The boundary of Areas 8-2 and 9, north of Edmonds) and Mukilteo State park. The shoreline is indented, forming somewhat of a small bay, and that's where the "hollow" part got it's name. Come mid-August you'll see more boats in that area than just about anywhere else at any time of year!