OceanCalc

True Wind vs Apparent Wind Explained

How boat motion changes the wind you feel and why it matters for sailing.

Author: OceanCalc Editorial Team · Publisher: Albor Digital LLC

True wind is the wind you'd feel if the boat were stationary. Apparent wind is what you actually feel—it's the vector combination of true wind and the boat's motion. When sailing upwind, apparent wind is stronger and comes from farther forward than true wind. When sailing downwind, apparent wind is weaker. Your sails and instruments respond to apparent wind, so understanding both is essential for trim and tactics.

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Frequently Asked Questions

  • Why does apparent wind increase when sailing upwind?

    Your boat is moving into the wind, so your forward motion adds to the wind you feel. The apparent wind speed is greater than the true wind, and the apparent wind angle is narrower than the true wind angle.

  • What instrument shows apparent wind?

    The wind indicator (wind vane) at the masthead and most electronic wind instruments display apparent wind speed and angle. True wind is usually calculated by the instrument from apparent wind and boat speed.

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