I can't find "doictionary" anywhere either

I thought that using a WAAS enabled gps eliminated the "built in error" factor? The course I have in mind is at least 1km, probably more, so "minor" errors won't have a large impact on the overall result. The original arguments revolved around a difference of speed of around 10 knots, so we should be able to tell the difference between 20 and 30 knots for instance over a 1 or 2 km distance.
Only another month before the ice is off!
Al