We grabbed (stole) this from the Global Sail Challenge. Good info here on weather routing.
One recurring question among the novice offshore sailor is how to optimize your route when sailing. The practice is known among sailors with the French name of Routage or the English name of Weather routing. We do not want to write an article that is too technical here because it partly depends on the navigation software you use.
However, we will try to understand the fundamentals so that you can find your route with any system.
To optimize the route you will inevitably need dedicated software. This is why this is usually a topic for long-distance racers. Mobile apps have also appeared recently so you can try them out to see if you are comfortable with them. The best-known navigation software among professional sailors are the following:
qtVlm (Free open source)