The compass direction the true wind blows from, independent of where the boat is pointing.
True wind direction (TWD) is the compass direction the true wind comes from, in degrees. A westerly wind blows from the west: TWD 270°. Unlike the wind angle, TWD doesn't change when you tack or alter course. It describes the wind, not the boat.
Calculation
TWD = heading + TWA (normalised to 0–360°)
Here TWA counts positive with the wind on the starboard side and negative on port. With a heading of 200° and the wind 45° on the starboard bow, TWD is 245°.
Why it matters
- Wind shifts. Watching TWD over time shows whether the wind veers (turns clockwise) or backs (turns anticlockwise), and on which tack you're being lifted or headed.
- Comparing with forecasts. Forecasts give wind direction the same way, as the direction it comes from.
- Logbook entries. Wind direction belongs in every logbook entry, together with wind strength on the Beaufort scale.
Manta does this for you
Plotter data on your iPhone over WiFi
Connect your plotter or a WiFi gateway, and Manta shows your instruments live and records wind, depth and speed through the water on every trip.
