Layering escorts against E-boat attacks

E-boat formations could be substantial, but an action involving forty or fifty boats is treated as exceptional. Groups of roughly a dozen to thirty were more characteristic, and Britain increasingly met them with Vospers and numerous Fairmile Bs. Trawlers, corvettes, and V and W-class destroyers added heavier escort capacity around the same coastal traffic. E-boats added one lethal layer to waters already threatened by mines, aircraft, and submarines. A quoted wartime account puts more than half of British ship losses and 40 percent of tonnage losses close to home, which explains why this mixed defensive system was indispensable.