11 September 2023
A Polar diagram describes how fast a sailing boat may go at different wind speeds (TWS) and in different angles to the wind (TWA).
Axiom displays running LightHouse 4.5 or higher include over 500 sets of Polar Performance Data for popular sailing hulls preloaded. If your hull is preloaded in Axiom, choose your yacht brand and model and enjoy the advanced features polar performance data enables, such as tack angles to achieve optimum VMG upwind and downwind, time and distance to tack, and the percentage of polar boat speed being achieved. The latest list of Axiom's preloaded Performance Polars in the LightHouse operating system is available in this knowledgebase article.
Polars, also known as a polar diagrams, describe how fast a sailing boat may go at different wind speeds (TWS) and at different angles to the wind (TWA). Every type of yacht has its polar diagram (or VPP, velocity prediction program), computed from hull shape, weight, rigging, and sail setup. Axiom uses this polar diagram information to calculate the fastest choice of path for the current wind speed and direction.
Knowing your boat's optimal performance parameters will enable you to identify the quickest route between two points by leveraging your target speeds and wind angles, from which you can also derive your laylines. The Velocity Made Good (VMG) principle demonstrates that traveling in a straight line often is not the most rapid solution, and sailors may wish to use their boat's performance to its best advantage. Axiom's dynamic layline display enables sailors to maximise their VMG, displaying how far they need to sail on their current tack to reach their target waypoint after tacking and considering wind conditions.
With the latest release of our LightHouse OS, Axiom users can import polar diagram performance data via a spreadsheet in .csv file format and microSD card directly into their Axiom display. Once polar performance data is uploaded, you can manually adjust polar values or upload multiple polar tables for different conditions, such as inshore, offshore, or short-handed sailing.
Use this sample polar table spreadsheet to upload your Polar Performance Data to Axiom. Polar data can be sourced from many locations. Your boat manufacturer (which is the preferred source), a class association or members forum, a rating certificate, or put together by the owner if it is a very old hull design or a one-off boat.
Know when to add or remove sail with Automatic Sail Plan Recommendations and keep your boat optimally tuned no matter what the conditions.