[CA] [CA11] advanced sailing tools

[Chuck - Raymarine - Moderator]

Tack Heading is the heading to steer to mirror the current true wind angle on the opposite tack.

I think it is also commonly called Tack Course.

The calculation is: Tack Heading = (Magnetic Heading + (2 * True Wind Angle)) % 360

So if the heading is 10° and the true wind angle is 30° to starboard then in order to get a true wind angle of 30° to port the boat would have to steer a heading of 70°.



In LightHouse II, the user can configure the Chart application to be overlaid with laylines. These show the best angle to take to tack towards a waypoint. (There are a number of layline types – I can describe further. One of them just mirrors TWA). In the example below, the boat cannot head straight to the waypoint, so must tack. The most efficient tack legs will be along layline 1 to point A then along layline 2. The STEER TO LAYLINE databox is suggesting turning 25° to starboard in order to sail along layline 1.