True wind on eS128

[Chris Klamann]

I use an Airmar PB150 ultrasonic wind sensor. Previously I had it connected to C90W, then e97 displays and both were capable of displaying apparent and true wind (speed + direction). I do not have a speed-through-water sensor which is usually necessary to calculate true wind. Instead Airmar sensor provides NMEA messages containing true wind data already calculated. Recently I switched to eS128 display with newest software installed and unfortunately it does not display any true wind data. As I'm aware of some nomenclature issues, I've tried to display Wind over Ground, but this didn't work either. Is it a software bug or does my new eS128 requires different setup compare to previous e97 ? NMEA buffer recording shows $WIMWV (T) message received: (...) $WIMWV,14.7,T,1.3,N,A*15Rx (...)

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Chris,

Within performance sailing, True Wind data (sometimes called True Relative to Boat—is Apparent adjusted for Speed Through Water and Heading) requires speed through water data. Please click here to view a FAQ addressing this subject. As the Airmar PB150 does not feature a speed through water sensor, it would not be capable of calculating the through water vector and would thereby actually be reporting wind speed with respect the vessel's motion over ground ... this is not True Wind per the definition specified above. Should you supply a sample of the complete NMEA 0183 sentence transmitted by the Airmar weather station, I will backfeed it into both a C90W and an eS-Series MFD to see how each responds.