Scale of Attack on the East and West Coasts of North America. Note by Secretary. (C.I.C.34/1)

undetected the shipping lanes in the coastal zone or a shore objective. The chances of reaching the shipping lanes in the coastal zone are better than those of penetrating within effective gun range of a shore objective. It is most unlikely that either type, if at large in the North Atlantic, would attempt operations against objectives within the North American coastal zone in preference to attack of shipping on the ocean routes. Any relaxation of patrol activities would probably be taken advantage of by submarines rather than by surface vessels.