[CA] [CA11] Is True Wind data present on Seatalk?

[jackdaw]

Hi there,

I am wondering if True Wind data (TWA/TWS) is present on the seatalk network if SOW is present to allow the networked wind instrument (ST60+ in this case) to calculate it? I have seen lists of reverse-engineered seatalk sentences that would suggest it is not.

If this last statement is true, it means that any networked device that needs true wind (like an AP) must calculate it for itself using SOW and the apparent wind data the wind instrument emits.

I'm looking to display true wind data on a 3-party NMEA display... I have all that worked out, but it relies on seatalk data that it can translate into a MWV,,True sentence.

Thanks!

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Jack,

Like most autopilot's Raymarine autopilots do not use true wind. When operating in vane mode, these autopilots use apparent wind. The SeaTalk communications protocol wind data packets only feature apparent wind data. The interfaced devices calculate true wind data from apparent wind and speed through water data.

[jackdaw]

Of course you are right about the AP steering to AW only, not sure what I was remembering.

While a pain for me I can see why TW data is not broadcast; its accuracy is based on available input. A device with angle of heel sensor would be more accurate, but would compete with a wind instrument broadcasting less accurate data.

Thx,

[Chuck - Raymarine - Moderator]

You're welcome.