The Power of Sailing Math at Your Fingertips
A potent sailing tool is now available in your Leopard’s electronic navigation system.
Raymarine is adding the polar diagrams for all Leopard sailing catamarans to its Axiom LightHouse chartplotter software, effective with v. 4.4, which is expected to be available for download on March 20, 2023.
A polar diagram shows how fast a sailboat could potentially travel at different wind speeds and various angles to the wind. Every sailboat model has a unique polar, which displays the results obtained using a velocity prediction program (VPP) based on the craft’s weight, hull shape, rigging and sail setup. The calculations in your boat’s polar diagram are a powerful tool for charting a course, estimating passage times, and choosing your sail plan for maximum efficiency.
The Leopard polars in LightHouse should be predictive of your boat’s performance because Leopard provided them, says Raymarine Global Product Manager/Multifunction Displays Will Sayer.
While it can take a bit of time and effort to understand polars, the juice is worth the squeeze, says yacht designer and naval architect Alex Simonis, who has been deeply involved in designing Leopard sailing catamarans.
A polar diagram allows you to maximize your Leopard’s performance in all wind conditions. You can determine if a sail change is in order by checking your current speed against the maximum speed calculated in the polar. Using the polar can help you better understand your catamaran’s ideal configuration for various conditions.
For example, says Will, when combined with Axiom’s layline function, the polar can help you find your Leopard’s sweet spot angle when sailing up or downwind.
“It’s a really good tool to help you learn about your boat and boost your confidence that you are doing things right,” says Alex. “By experimenting with sail changes and keeping an eye on how your speed is doing versus the speed calculated by the polar, you will learn exactly when it’s better to make a sail change, rather than guessing.”
Of course, as Will Sayers notes, manually comparing your boat’s performance with the polar data in real-time can be difficult if the chart is on paper or a separate digital device. That’s why integrating your polar into your Axiom chartplotter is so exciting.
Alex echoes that sentiment
“The possibilities for using your polars are endless with a system where you can instantly see the difference between actual and projected boat speeds,” says Alex. “It allows you to trim sails and steer a bit differently to immediately see if you are getting closer or further away from your target speed.”
Based on the above, you’ll probably agree it’s time to jump on the polar express.
If you have questions or problems downloading LightHouse v.4.4, contact Raymarine Support.