Course to Steer (CTS) - use this when you want to find the course to the next destination - in the future. It takes account of tide, and the leeway due to wind. The principle of the CTS drawing is that if you start at A, and let the tide carry you to D during time T, you can get back to the required track by sailing or motoring at your boat speed for time T to cross the track. Aiming at the destination B from D cannot achieve this in the same time, so don't do it!
Course To Steer process YM.pdf Course to Steer example
Click HERE for animated diagram of Course to Steer.
Leeway is estimated by comparing the centre line of the boat with the wake:
If you need to find distance, time or speed use the 'Distance / Speed / Time' circle:
Cover the required value and the circle gives the equation for that value.