Some Geography 17

The English Channel ("La Manche" in France) is an 'arm' of the Atlantic Ocean that links the southern part of the North Sea by the Dover Strait at its northeastern end.  It was formed by a complex structural down-folding from c 40 million years ago though geologists debate that its downward tendencies began as early as 270m years ago from off-and-on movements of the glaciers, rock and ice.

Its deepest point, Hurd's Deep, is 180 meters below sea level (the average depth is 63meters). The Chunnel, for context, is sunk to 75meters. By contrast, the Channel is 560km long and 240km wide at its extremes; the narrowist, where I will swim, is 35km from Dover to Calais.

The surface area measures 29,000 square-miles with water volumes of approximately 2,200 cubic miles so, basically, the Channel is a giant funnel that boosts the tidal range (the difference from high to low water) from less than a mater at sea level to over six meters.

Rusty checks out the Dover Cliffs, below. It is the kind of day I am hoping for.