How to Plot a Course to Steer

Competent chart work is important. Not just because you should know how to navigate using a paper chart, but also because it's important to understand how the forces of nature act upon your vessel and, therefore, enable you to better shape your course.

In this short video, we talk you through how to apply the tidal vector and boat speed vector to reach a desired destination efficiently, by steering just one heading for the entire tack. For a longer tack, in open water, we'd use hourly vectors for tide and boat speed, but in this example we show how you can scale down the vectors into ¼ hour (15 minute) vectors and still achieve the same course to steer (CTS). This is useful when using a smaller scale chart.

After you have applied tidal and boat speed (through the water) vectors, you then apply the estimated leeway to the water track ( > ) so that we arrive at a final course to steer adjusted for both tidal effect and leeway.

Remember, when applying leeway, if the wind is on the port side, you reduce the CTS by the leeway figure and if the wind is on the starboard side, you increase the CTS by the leeway figure (see illustrations below).

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