I have a i60 Wind Indicator. I also have a i50 speed indicator and an e125 Multifunction Display. The speed transducer got fouled and the speed indicator read zero. I noticed that this caused the Wind Indicator to read the same for the True and Apparent Wind. Does the Wind indicator use the i50 speed to calculate the true wind? It seems like it should use the COG and the SOG from the Multifunction Display (GPS). Otherwise, the Wind Indicator would indicate true wind plus current, not the true wind.
True Wind calculations are produced by Speed Through the Water, not Speed Over Ground. So it will required Speed Through the Water data, and it is the cause of True and Apparent reading the same. Using SOG for speed, would be calculating Ground Wind Speed.
Sure would be nice to have a choice of using SOG or STW. Like I had on my old NAVman Wind that i just replaced with an I60. Hardly use STW were i am.