Dont remember the exact year but apparently what happened but was that the storm located just off Cape Charles (the upper part of the Ches. Entrance near Norfolk, VA.) and the counterclockwise winds simply 'emptied' the bay ... or so the 'local history books' have stated. Many at that time went out to the partly drained bay and located many lost items - boats, gear, etc. until the water returned.
On a very strong and sustained NW'er the Bay can drop 2-3ft and on a very strong SE'er it can rise 2-3ft. Apparently the storm that hit just above Cape Charles produced sufficient NW/N winds on the 'land side' of the storm to cause the significant drop in water level in the Ches.