Predict Wind

[s/v Jedi]

Originally Posted by donradcliffe

I got the same routing results while using the offshore predict wind this summer coming back from Hawaii. As I remember, it had me at 15 degrees TWA in 12 knots of wind 1000 miles from land. I can't remember whether turning off the motoring option helped, but it seemed like a programming bug at the time.

It may be a bug that sneaked in as I have not used the program for almost two years now.

[AllenRbrts]

I ran a quick experiment. I put in a short route directly upwind. Asked it to do routing with and without motoring enabled.
With motoring enabled, it came up with a route directly into the wind... it is the fastest way to get there (5hrs). Without no motoring enabled, it tacks back and forth and arrives in 7 hrs. It is not a bug, but instead solving the problem it was given, fastest way from point A to point B.

Edit...

I think it is confusing about PW's motoring parameters. I have thought they were "I will motor if my speed through the water is below X knots and my motor speed will be Y knots". Instead, I think what it really means is speed towards the destination, not speed thru the water.