Yourbestsailvideo
Polar curves
1 November 2023 · 12 min · 2K views
What this video covers
Polar diagrams represent a sailboat's theoretical performance across various wind speeds and headings.0:28 These charts use radial lines to indicate the angle of the boat relative to the wind and concentric semicircles to denote boat speed in knots.0:48 A typical polar curve illustrates that maximum speed usually occurs on a reach, between 100 and 105 degrees off the wind.4:12 While theoretical diagrams often show performance at extreme angles, real-world sailing is limited by the boat's ability to maintain flow over the sails; at approximately 45 degrees, the boat reaches its maximum upwind capability before stalling or losing speed.4:52 The Velocity Made Good (VMG) is optimised by identifying the point on the polar curve where a horizontal tangent meets the performance line.6:49 For downwind travel, the most efficient path often involves gybing rather than sailing dead downwind, unless the boat is rigged with a spinnaker or a poled-out genoa.9:11 Manufacturers provide baseline polar data, but competitive sailors must record performance over multiple days in stable conditions to generate accurate, boat-specific curves for different sail configurations.11:29
More from Yourbestsail
From Yourbestsail — see the channel’s boat, crew, and every analysed video.
The Sailing Directory Newsletter
One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.