When you plot a course using the heading timer, you plot an estimated course that your boat will likely follow in the hours to come. This is because a number of factors may change in the hours following your programming.
The only data that will not be affected by changes other than those you make are the times at which the heading changes, and the value of the heading (or wind angle) you will enter.
For instance: if you plan a course change to 214 at 18:14, your boat will follow this course at the requested time.
In fact, the actual coordinates of your boat are constantly subject to the weather forecast, which changes as time passes. Your coordinates also depend on the manoeuvres carried out (sail changes, etc.), which can also affect the speed of your boat.
If you set a course change with a wind angle locked at a 57° wind angle at 2:16 p. m., this wind angle will be used at 2:16 p. m. along with the wind at that time, which may be different from the wind forecast at the time of programming.
At the time selected in your programming, it may happen that the coordinates where the change should take place as initially displayed on the map will be a little closer, a little further away or the trajectory followed will be different from the one displayed on your screen when you programmed it.
This is why you should be careful when using this instrument in unstable weather or in coastal and island areas also when navigating around buoys.
If you need "geographical" accuracy, we recommend using waypoints, which will allow you to navigate safely and avoid accidental grounding or missing a buoy.