It is not widely remembered that mines were by far the most effective weapon deployed against the Royal Navy in WWI. They cost us 5 battleships, 3 cruisers, 22 destroyers, 4 submarines and a host of other vessels. They were in the main combated by a civilian force using fishing boats and paddle steamers recruited from holiday resorts. This unlikely armada saved the day for Britain and her allies. After 1916 submarine attacks on merchant ships became an even more serious threat to Allied communications but submarines were far less damaging to British warships than mines. AUTHOR: Jim Crossley is a retired engineer and a keen sailor. He has a history degree from Cambridge and has previously written a novel Something Wrong with our Ships and a book on early British destroyers to be published by Osprey. SELLING POINTS: A mainly civilian force operating commandeered small craft. Played a vital part in the defence of British waters in WWI. Full of outstanding seafaring characters. ILLUSTRATIONS: 10 plus charts and diagrams