Tried to run optimal on a 6 mile course, including some legs that are relatively short, probably shorter than the GRIB resolution. 

Noted that the grid dimensions were greyed out, but set the time steps to 0.01 hours, to force evaluation at roughly 30 sec intervals. 

It created a course, and some of the legs made sense, others were showing a TWA of 4 degrees, 
Any thing I can do differently ?