Layline

A layline is the imaginary course from a sailing boat to a mark, waypoint, headland, or safe turning point that the boat can reach without making another tack or gybe, given the current wind angle, boat speed, and sea conditions.

Good layline judgement reduces wasted distance and helps avoid overstanding, pinching, or being swept below the target. It is especially important when sailing Upwind, where small changes in True Wind Direction or Tidal Current can move the layline significantly. For racers it affects position and timing; for cruisers it can determine whether a headland, harbour entrance, or waypoint is safely reachable.

PredictWind forecasts, high-resolution wind maps, tidal stream data, and routing tools help sailors assess how laylines may change before and during a passage. Combining forecast wind shifts with boat performance data supports better tactical calls and more efficient Weather Routing.