5. At Annexe C is a more detailed account of the enemy's present defensive measures. 6. Further, there are numerous elementary anti-invasion devices which he has yet to adopt (beach-scaffolding etc.). It is even possible that a defensive system in depth, including defensive positions in the interior, might be organised: but the coast line itself must remain by far the best defensive line forward of the German frontier itself. Defence of the coast will pivot on the ports, which will probably be converted into quasi-fortresses, with all-round defence.