The Chesapeake Bay, at 180 miles in length, is one of the great protected waterways of the country. Because of its natural configuration it became the home of many of our earliest ports of call: Norfolk, Portsmouth, Annapolis, Baltimore and, farther up the Potomac, Alexandria and Washington. These were all bustling seaports early in the beginning of our nation. But for all its size, Chesapeake Bay is shallow in many areas, with limited deep water channels. The need for aids to navigation was evident early on.