Victory at Sea: Merchant ConvoyPreventing attacks on defenceless merchant ships is the other main role of the navy, and it was here that the war was fought, day in and day out, by the humble corvette, frigate and destroyer escort, and later by escort carriers. Commerce raiding formed a critical part of the strategy for several nations Germanys Kriegsmarine almost brought Britain to her knees whilst the US Navy similarly strangled Japans movement of industrial goods, materials,