Files installed
UIGraduations.dds
UIButtons.dds
UIButtonsSelectedFocus.dds
UIBodyLightMap.dds
Abreviations.
TWA True Wind Angle. It is the angle of the real wind compared to the axis of your boat.
HDG Heading. This instrument is a numerical compass and indicates the course of your boat.
CNM Course to next mark. Displays the course to reach the next mark.
The head up display already gives us the layline to the next mark..CNM
The opposite tack heading calculator is an aid to quickly calculating if we have reached the layline.
Overview of how to use the opposite tack heading calculator.
On the compas there are preset blue lines representing TWA's of 30, 35, 40 and 45 degrees.
Turning clockwise in the tack then read the new heading on the right side of the Compass.
Turning anticlockwise in the tack then read the new heading on the left side of the Compass.
Reading Accurately the new heading from a blue TWA line.
The compass is marked every ten degrees. If the blue lines representing the new heading on the opposite tack falls between the the compass markings then HDG in the head up display will supply the unity digit.
Example
We are sailing on starboard tack with a TWA of 30 degrees.
The preset blue line representing the new port tack heading at a TWA of 30 line falls between 30 and 40 on the compass. The HDG in the hud is 335 so 5 is the unity value.
Therefore the accurate reading of the heading on the opposite tack is 35. Simply Put Unfortunately we do not always sail at TWA's of 30, 35, 40 and 45 degrees!
Turning clockwise add twice the difference between the real TWA and the preset TWA.
Turning anticlockwise subtract twice the difference between the real TWA and the preset TWA. Detailed example on starboard tack On starboard tack at TWA 32 degrees to the wind at a heading HDG of 326 degrees.
Read the new port tack heading for a TWA of 30 degrees. This is 26 degrees.
 To adjust this result to the actual TWA of 32 degrees add twice the difference between the real TWA 32 and the preset TWA 30.
In this case the difference between the real TWA and the preset TWA is 2 so add 4 The new heading on the port tack will be 26 degrees + 4 = 30 degrees. Detailed example on port tack On port tack at TWA -32 degrees to the wind at a heading HDG of 31degrees.
Read the new starboard tack heading for a TWA of 30 degrees. This is 331 degrees.
To adjust this result for the actual TWA of -32 degrees Subtract twice the difference between the real TWA 32 and the preset TWA 30.
In this case the difference between the real TWA and the preset TWA is 2 so subtract 4 The new heading on the port tack will be 331 degrees - 4 = 327 degrees.
Simplification
Turning clockwise read the new heading on the right of the compass and add twice the difference between the real TWA and the preset TWA.
Turning anticlockwise read the new heading on the left of the compass and subtract twice the difference between the real TWA and the preset TWA.
Original Idea by Ronin
Developement Ronin and Adoonis.
Thanks to the testers Wazzari and Art-Wales |