A Type XXI surfacing in the Potomac

What would happen if a German Type XXI reached the Potomac and surrendered just after Germany's capitulation?

The United States would be astonished and heads would roll because the submarine had penetrated several guarded maritime approaches undetected.

The counterfactual asks the submarine to pass through the Chesapeake entrance, by major naval facilities, up a heavily used bay, and into the Potomac before showing a white flag. The speakers expect British amusement but American shock, investigations, and dismissals throughout the watch and coastal-defence chain. Fishermen and other local traffic would create additional chances for discovery, especially in waters still alert to submarine attack. Reaching the Potomac would expose failures in geography, base defence, civilian observation, and command accountability.