
Post by
zezo | 2020-11-13 | 11:19:37
Info in the popup boxes is averaged somehow. With the interpolated wind the numbers change all the time, so there would be a dot every 10 minutes. That's why the wind direction, twa and hdg don't always add up to 360.
In may cases you want to consult the polars about optimum VMG angles. Or watch the dots on the green line - they fall behind the isochrone lines if you get outside of the optimum race.
If sailing in fixed direction instead of fixed TWA use the red/blue line to get the average long-term direction, also to check if a straight route is not equivalent to a slightly curved/turning one.
The router thinks in 5-degree increments, so it won't sail TWA 63. Will alternate between 60 and 65. But sometimes it will alternate between 60 and 70 for a reason if there is slow spot at 65.