Of the former sub-bases you does not see much today, only in Kiel you can see the ruin of the subpens. In Wilhelmshaven the area of the former subbase is now a public beach, bar, restaurant area. The subpens in Hamburg are gone now and on that area is the new container terminal located.
Next to my house in the forrest is the former torpedo and ammunition camp for the WWII sub-base Hamburg. Today you can see there only some destroyed shelters and barraks and maybe deers.