Please select your home edition
Edition
Henr-Lloyd BLU LEADERBOARD

Global Solo Challenge: Weather routing - how to optimise your route based on weather predictions

by Global Solo Challenge 23 Aug 02:54 PDT
Route to Cape Horn © Global Solo Challenge

One recurring question among the novice offshore sailor is how to optimise 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.

The software to optimise the route

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:

Optimising the route: understanding the problem to be solved

Let's try to get to understand how "Weather Routing" or "Routage" is done step by step. First of all, let's ask ourselves what is the problem we need to solve to optimise the route. We have to go from point A to point B in the shortest time possible. The variables are the intensity and direction of the wind and obviously our boat. Initially we can see it as an instantaneous problem. That is, in relation to the weather conditions we are observing at that precise moment.

However, unless you have to go to a rounding mark, the problem is not instantaneous. On a long course the boat performance details is the only variable that remains constant (save for damage to sails etc), but the variables wind direction and intensity change over time. For this reason we have to divide our potential route into many steps. Starting from point A we will be able to navigate in a number of directions that fan out in front of us. All the points that I could reach with my boat in a defined period of time is defined an isochrone. For simplicity we say that the first isochrone defines all the points that I can reach after an hour of sailing.

At that point, the software, starting from a series of points on the isochrone, repeats the exercise from each point. From each point a range of new possible routes will open up. The maximum distance boundary given by the sum of the navigation in the first and second hour defines the second isochrone. Proceeding by successive steps, the navigation software will arrive at its destination. Working backwards through the series of segments that defined the fastest route we have the outline of the optimal route. It is an empirical solution to the problem, because trying a mathematical solution would be impossible.

Continue reading the full article here...

Related Articles

How to apply antiskid on deck or paint numbers
More lessons and tips from the Global Solo Challenge In many classes such as Mini 650s, Class40s and Imoca60 it is mandatory to paint your boat number on the deck, in Cat Zero events you also have to paint an area of 4sqm in high visibility colour. Posted on 17 Oct
Knock-downs, capsizes, 360s, dismastings
Everyone who has sailed has certainly wondered what would happen if the boat overturned Everyone who has gone by boat has certainly wondered what would happen if the boat overturned. Just think about how many times I have asked myself this before leaving for the Global Ocean Race. Posted on 9 Oct
Global Solo Challenge: Battery & power management
Almost every sailing or motor yacht has on board a more or less complex electrical system Almost every sailing or motor boat has on board a more or less complex electrical system and a variable number of batteries. This depends on the size of the boat, the instruments installed and the equipment on board. Posted on 29 Sep
Global Solo Challenge: Facing Cape Horn in a storm
A story of rounding the famous landmark After the second storm, the wind dropped rapidly, and within half a day it went aft and we could even hoist the big gennaker. Hugo and I celebrate, laugh, joke. Posted on 27 Sep
Global Solo Challenge: Pasquale, gentleman sailor
Pasquale De Gregorio embodies a dream, that of racing the most extreme solo race Pasquale De Gregorio is one of the closest sailors to all lovers of the sea and sailing. Pasquale is an example, he had to conquer the sea, he was not born near it, it was love at first sight, which lasted a lifetime. Posted on 25 Sep
Sail changes on an offshore racing boat
Sail crossover is a term used to refer to a boat's combination of sails for all conditions Sail crossover is a term used to refer to a boat's combination of sails for all conditions. Each sail has a range of use, beyond which a smaller sail will replace it. Posted on 18 Sep
Global Solo Challenge welcomes 35th entry
For François Gouin, sailing is an incredible school of life François Gouin from Pornic in France is the 35th entry in the Global Solo Challenge with his Pogo 40S Kawan3, a first generation Class40 (Finot-Conq) built in 2008 by Structures. Posted on 15 Sep
Jean-Luc Van Den Heede interview
An in-depth analysis of solo sailing and of the problems to be faced such as food and sleep A long interview with Jean-Luc Van Den Heede, the last seadog, the man of records and the "long route" who talks to us about the mother of all non-stop solo circumnavigations. Posted on 13 Sep
32nd entry for the Global Solo Challenge
The momentum of the event continues to grow The momentum of the Global Solo Challenge (GSC) continues to grow. Organisers are delighted to announce that the 32nd entry is also the 3rd Australian skipper, with a 50+ foot performance boat, who at this stage wishes to remain anonymous. Posted on 6 Sep
Global Solo Challenge: What is an AIS?
An essential instrument for safety on a sailing boat The acronym AIS stands for Automatic Identification System. It is used by ships, pleasure boats and traffic control stations. The system allows information on the position of nearby ships and shore stations to be exchanged electronically. Posted on 4 Sep
Coast Guard Foundation FOOTER 3J Composites 2020 - FOOTERZhik 2021 Season 2 FOOTER