Any Navy people out there who can comment?

Well, I'm not navy but I have read quite a bit about naval activities.

Mines were first used in great numbers during the first world war. Since the British navy depended on clear shipping lanes to transport troops and equipment to France, Flanders and the Dardanelles the German, Austrian and Turkish navies promoted the production of specialist mine laying ships. To counter this the British developed a new type of small ship to accompany destroyers and carriers - the minesweeper. The first ones probably consisted of nothing more than hastily converted sloops but, as the war progressed, it was clear that equal priority had to be given to minesweeper production as to the production of destroyers.

The intervening years between the wars allowed for more advanced naval teachniques, technology such as the sonar and ship designs to evolve and the present minesweeper design came into being.