The Header/Lift functionality in MAX differs from most other systems in that it does not use wind data to determine if there is a Header or Lift but instead Header/Lift are given relative to the set Course Axis. This means that Header/Lift information given by MAX is not used to give feedback about how the boat is being sailed relative to Wind Axis but relative to Course Axis instead. Using this information the skipper can find the optimal Course Angle to sail at and increase their VMG. In this article we explain how MAX determines a Header or Lift and what having a Header or Lift means in the context of sailing with the MAX.
With both Course Axis (Menu>Racing>) and Course Angles set (Menu>Performance>). In the illustration above, the Wind Axis is +10° relative to Course Axis and upwind Target Angle is 45°. With the boat sailing at it’s Target Angle, relative to Course Axis it means MAX will give a +10° Lift sailing port side (Figure A) and -10° Header sailing starboard side (Figure B). Indicating that sailing port side, into a Lift relative to Course Axis, you will be able to sail at a smaller Course Angle, 35° as opposed to (-)55°, and increase your VMG. The figures C and D below illustrate Header/Lift when sailing downwind with a 135° downwind Target Angle.
When sailing with Headers and Lifts relative to Course Axis the rules are the same as relative to Wind Axis, going upwind tack on a Header (negative value), going downwind jibe on a Lift (positive value). While the MAX Header/Lift function relative to Course Axis does not assist in sailing at a specific Target Angle, it can assist in finding your Course Angle quickly after a tack or jibe. Using figure A and B sailing upwind, coming from a -10° Header and the boat at it’s Target Angle, tack into a +10° Lift. Respectively sailing downwind you jibe from a +10° Lift into a -10° header.
When MAX displays a negative value it indicates a Header, a positive value indicates a Lift.
The Header/Lift functionality has been implemented relative to Course Axis because the MAX is first-most designed for competitive sailing where many classes do not allow the use of wind data. In the article How to: Check Target Angle using Wind Data we explain how to use MAX to find your Target Angle when the boat is equipped with a wind sensor.