It was back to school again today, out at Ottignies, in a second nine-till-six lesson on such themes as meteorology, nautical instruments, first aid at sea, map reading and navigation, in our search for the qualification of Brevet de Conduite (chef de bord côitier et hauturier). Should I tell you how tiny Belgium has one set of rules for sea-going vessels, another for inland waters, a third for its coastal waters, and others for the lower maritime Scheldt, the Meuse, the Gand canal at Terneuzen and even for the Brussels ship canal? Should I tell you that each uses a different vocabulary, that there are significant differences in rules and signals and that the examiners expect students to memorise everything?  No matter. My illustration will be familiar to all seasoned mariners. It was the moment our teacher told us the difference between true North, magnetic North and compass North. You all know, don’t you? What? You don’t? Well, obviously, Cv = Cc + D + d, where D = declinaison and d = deviation. Come on! Wake up at the back!