I was lucky enough to have two glorious years shell fishing from Jersey, but based mainly in Alderney, including the wonderful Summer of '76. During that time I got to know the waters very well, with a good knowledge of all the rocks. (Just the place for crab & lobster)! In 1985 I took a 7000 ton cargo ship down through the Alderney Race and managed 23 knots almost to Ushant. This was on the full bore tide and was most exciting, with all my local knowledge to the fore. It knocked quite a few hours off my ETA in Portugal and I was the sole ship in those waters. Not to be recommended at low water Springs, though. Sometimes Navigation can be quite fun. On reflection, I think my crew were rather terrified, poor souls! I even hove to and got a box each of live crab & lobster from my Jersey buddies, in exchange for a bit of duty-free. We ate well for a few days!