Why limpet mining could disrupt the Allied war effort

A limpet-mining campaign could seriously disrupt the Allied war effort, particularly in 1942. Once attached covertly to a hull, the weapon's nature leaves defenders with fewer useful countermeasures than they might expect. German attempts to insert conventional spies and saboteurs into Britain or the United States faced substantial access and security problems. Delivering commandos by submarine could bypass several of those obstacles and place the attackers close to maritime targets. The danger comes from combining a difficult-to-detect weapon with an infiltration method suited to coastal operations.