RagnarJW wrote:

I have not found a way to point the GNX displays to use a certain source for data.

Menu > Setup > Data sources.
 

Nick is correct that the current firmware is only streaming data in 0183 format - however it is on their roadmap to stream native data in the same format as their NGT-1 n2k>usb adapter so all hope is not lost. Unfortunately, I don't have any timeline on when this might happen...

It's worth noting for anyone stuck with this in the future that many of the 'smart' depth transducers can be calibrated internally, as well as most systems being able to calibrate the received depth and rebroadcast - This is why people are finding more than one calibration value. Its worth checking your sources and seeing whether your display is pulling depth from a processor, or directly from the N2K bus and trying to standardise this, and to pick a calibration point and stick with it rather than mixing and matching.

Keith: Suggest you get in touch with Diverse Yachts in the UK. They have custom firmware for one of the Garmin 4" displays that allows streaming all instrument data to the Quatix over wireless Ant+,  including custom channels from Expedition.

Something to add to this: Calibrate Calibrate Calibrate.

Before you can start to use the numbers for performance you really need to be able to trust the numbers and the vast majority of boats I'm involved with massively under estimate the time and effort required to really get this right.

Understanding when the numbers might be wrong, and when they are probably right but actually showing something unexpected is critical and much of the role of the navigator is communicating this effectively.