At the mouth of the Severn River, where it meets the Chesapeake Bay, Annapolis is a center of recreational boating activity, and summer weekends witness heavy traffic of diverse watercraft. Yachting and associated businesses play an important role in the local economy, replacing the former influence of water-borne transportation. Marinas and boat yards line Spa and Back Creeks, and the US Naval Academy occupies more than two miles of waterfront on the Severn River, and Spa and College Creeks.
In spite of the urbanization of this part of the watershed, crabbers set their pots and watermen harvest oysters in the Bay less than two miles from the Annapolis city dock. East of Annapolis lies Whitehall Bay, technically within the Severn watershed but directly open to the Chesapeake. It is bounded by shoals used by recreational and professional fishermen, and provides a favorite anchorage for boaters. Proceeding northwest from Annapolis up the Severn, the 1/2 mile width and 25 feet depths are comfortable for recreational boating, and the high banks attest to the Scenic River designation Two tall highway bridges span the Severn in its first two miles. After about five miles the river opens up into the two mile diameter Round Bay, containing St. Helena's Island. Continuing northwest above Round Bay for another two miles, the Severn narrows abruptly and becomes shallower. Throughout its length, waterfront communities use the Severn for swimming and boating. The estuary ends near Interstate 97, where Severn Run provides the major freshwater input to the tidal Severn.