NavList:

Thanks Bill,

yes, you are right.Ocean racers do need the maths as you suggest, and even during  our local  cruiser race from Penzance, round Scillies, I've been known to draw polar diagrams with the help of calculator, GPS/ Autopilot, slide rule etc.But my dinghy (Laser)  sailing son usually corrects my course by "feel" of the wind ,tide, leeway etc and gets a better result than with  my poor maths.

Good doctors, (occassionally me included!) can often feel or smell a diagnosis quickly, without going through the full , step by step process required by the inexperienced. Some sort of short cut pattern recognition I guess.There is definitely an "art" to many skills.

Computers will no doubt better that one day, but not just yet, I  hope!

Francis