On sailing yachts they have an anemometer and windvane which connects electronically to a suite of instruments which include wind direction, wind speed, speed through water, depth etc. The wind indicator is capable of displaying both the apparent wind direction and true wind direction. I am sure that would work quite well on something bit bigger!
Last edited by srobarts; 21st May 2012 at 08:07.
Reason: correcting typo