[CA] [CA11] Instrument

[George Bailey]

When I turn up from dead down wind, the reported true wind speed on my i60 increases several knots. Clearly this is not what is really happening on the boat. Any ideas what’s wrong? Thanks!

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum George,

For the benefit of others who may be viewing this thread, please click here to view a FAQ addressing the requirements for calculating True Wind. In this case, it is recommended that your speed through water STW transducer be inspected to ensure that it's paddle wheel is not fouled and that it rotates freely. If so, then it would be recommended that STW (Speed) be re-calibrated. Calibration should be performed under slack water conditions and will accordingly only equal SOG under such conditions. STW sensors have non-linear error. Accordingly, the reported speed value will be closest to SOG when the vessel is operating under slack water conditions and at the speed of operation during calibration. Some more advanced STW instruments (ex. i70S/i70 MFIDs w/iTC-5 Analog Instrument Transducer Converter) support multi-point STW calibration to provide STW accuracy across a greater range of speeds.