 In the Port of London alone there are six such training centres, and for administrative purposes the United Kingdom is divided up into four main areas under the Naval Commanders-in-Chief at Portsmouth, Plymouth and the Nore, and the Flag Officer Scotland, each of whom has a Command Mine watching Service Officer.There are Port M.W.S.O.s in the various ports or areas with Section Officers, Chief Mine watchers, Leading Mine watchers and Mine watchers working under them.The R.N.M.W.S.