In the shallow water off beaches with gentle slopes, the Germans have embedded rows of steel stakes and wooden logs. They are set at an angle, their upper ends pointing outward from the beach. Submerged barbed wire and mines may be used in conjunction with these obstacles, which are intended to trap landing boats, or personnel who may be compelled to leave their boats to wade ashore.
As obstacles against landing craft, light booms of simple construction
are placed by the Germans in front of good landing beaches. They
consist, usually, of conical buoys, linked by wire rope that runs
through the tops and bases of the buoys. Rafts are similarly employed.
Explosives and warning devices may be affixed to these booms.