ww1 blockships and ww2 churchill barriers (causeway) used to protect the scapa flow anchorage, orkney, scotland

shore coast sea horizon wetland marsh reservoir plain grassland hill lake prairie bay grass field landscape cloud causeway barrier churchill blockships anchor blockship burray coastline diving europe farm farmland german graemsay great britain hoy island isle landmark mainland naval base ocean orkney islands outdoors scenic scotland scottish scuttled scuttling fleet ship ships south ronaldsay sunk sunken viking water world war ww1 ww2 vessels barriers used protect scapa flow anchorage uk#39aph39#s main wars