Bittern and Egret development leads toward Black Swan and Hunt escorts

The Black Swan class belongs to a continuous design lineage rather than appearing as a sudden wartime invention. Bittern-class work developed the sloop concept, while the modified Egret hull became the basis for later growth. The same experience helped define the requirements for Flower-class corvettes and Hunt-class escort destroyers. An earlier start to this design cycle would give the Royal Navy mature hulls, doctrine, and production knowledge before the Atlantic campaign opened.