
Post by
zezo | 2013-12-08 | 19:56:05
The track tool can be turned on/off via the toolbar button next to the zoom control
The tool plots three lines.
The red one is orthodromy to the cursor. Heading may change an may not be possible to do it in the game because of the fractional angles.
The blue one is loxodrome - course at constant heading.
The Green one is a plot wit fixed TWA (wind angle)
The colors of the numbers in the information box correspond to the colors of the lines.
There are dots/circles on the lines which correspond to the isochrone lines on the chart. Ideally you use the tool to find sailing angle which gives result no worse than the router itself.
The squares mean a sail change. They may not be 100% accurate, but will help you identify possible problems with the interpolated winds.
How to use it:
- It's often possible to reach the same point in few different ways - either fixed TWA or a straight line. You can choose the more convenient or see how much you will lose by not waking up at 4AM ;-)
- You can check for dips in the polar diagrams at sail crossover points. If the circles lie on the isochrone for certain range, say 45-90 degree but fall behind between 60 and 70 that usually means that it's faster to spend some time at 60 and some at 70 than sail at 65 all the time.