Axiom Wind Shift Display

Wind Shift Explained

Like most things in sailing, the wind does not remain constant in either strength or direction. Every shift in the wind requires the boat to alter its heading in order to maintain a close-hauled course. A shift that allows the boat to change its heading closer to the Mean Wind Direction is called a "lift"; a shift that forces the boat to change course away from the Mean Wind Direction is known as a "header." 

In an oscillating wind, a boat that regularly tacks when headed will spend more of its time sailing a lifted course and will sail a shorter distance to the windward mark than a boat that regularly sails a headed course. This gives the boat sailing in the lifts a considerable advantage.

In the diagram above, the boat on the right sails a shorter course by tacking when headed and thereby sailing mostly in lifts. Axiom automatically calculates the mean wind direction by averaging the true wind direction over a period of time. Sail your boat for maximum speed and use Axiom's Wind Shift data display to identify the headers and lifts to help you decide when to tack or gybe. Permanent wind shifts can be recognized as a constant header on one tack and a constant lift on the other tack. In this situation, you can reset the mean wind direction by touching and holding the wind shift data item and selecting reset. 

Wind Shift data displays on Axiom are available as a horizontal bar display on the chartplotter, in the sidebar, a floating data box, or as a Dashboard data item. Wind Shift data is also shared across the network to Alpha performance displays.