Second to this offensive mining comes the laying of large defensive fields to protect our own approaches and coastal sea routes and in the background the continual sweeping of these routes in the face of enemy minelaying.
The part played by escaping Dutch and Norwegian ships and personnel is rightly emphasised as is the Commonwealth contribution.
The US Navy joins in as its sweepers help pave the way for the North African, Sicilian, Normandy and other landings. We see how conventional sweepers lead the way to the invasion beaches but also how craft right down to the smallest landing craft have to be fitted out to combat mining in shallow waters, where influence mines on the sea bed replace moored contact and influence mines. In the Seine Bay alone over 900 mines were swept. The clearance of Cherbourg was a battle in itself.
This is a huge field to cover and the narrative is unavoidably selective while chronicling the losses and honours received. the whole is fully illustrated with maps and photographs, many of the latter from Lt Cdr Hoole's private collection and these you won't see anywhere else. The authors are both mine warfare specialists, a guarantee of a true bill. They succeed in creating not just an important contribution to the naval history of WW2, but a memorial to the thousands of participants in this aspect of naval warfare which often escapes attention in other works, but was nevertheless essential to our survival and then eventual victory.