The American Constitution was once famously described as the eighteenth century English constitution as misunderstood by a Frenchman. That Frenchman was the Baron de Montesquieu who presided over the powerful regional law courts of Bordeaux that were situated just a stone's throw from where the Caledonian Star moored overnight. Our location was perfect, at the heart of one of Europe's great historic river fronts, lined with splendid examples of eighteenth century architecture dating back to the time when this city was at the height of its powers. It grew rich on the triangular Atlantic trade in industrial produce (textiles and iron from Europe), slaves (from Africa) and raw materials (cotton, sugar, cocoa, coffee) from the Americas. In the eighteenth century it was, after London, Europe's second largest port.

Trade linked Bordeaux with England; the famous wines of this region have always sold well there where they are still known as "claret". Montesquieu, like the other writers of the French Enlightenment, was an Anglophile. What he admired about England was the separation of powers that historians now realize was not nearly as separate as Montesquieu supposed. Ideas spread around the triangular trade route as readily as goods and the American Revolution was greatly influenced by French philosophy.

Not all exchange between the Old and New Worlds has been beneficial. In the 1870s, disaster hit the vineyards of Europe when they suffered a phylloxera epidemic originating in America. The remedy was to graft French vines onto resistant New World stock, so today's Bordeaux wines are, in a sense, also New World wines. In the past 36 hours we have visited chateaux in the Medoc and in St-Emilion, celebrating these transatlantic links. This celebratory mood intensified as we cast our moorings this evening and headed downstream to the accompaniment of local cheeses and wines served on deck.