See Sailing performs it's calculations in a "water centric" fashion. Which is to say that speed is speed through water, heading is magnetic heading and the GPS velocity is not used for much. As a consequence the following channels need to be available in the data provided:
Timestamps
Speed through water
Magnetic heading
Wind speed, Wind angle
GPS location, SOG/COG
It is also assumed the log will be more than 60 seconds long.
And the following are optional:
Magnetic variation (sourced from the compass in NMEA data)
Pitch, Heel
Rudder angle
If not present, the magnetic variation will be assumed to be zero. This also relies on your compass being correctly configured although dual GPS/compass units (such as B&G ZG100 or Lowrance Point 1) often configure themselves.
The pitch, heel and the rudder angle will just not be present on the display if missing.
Expedition log did not contain expected streams may be returned. This is because expedition logs are very flexible and may contain data such as start line calculations. These logs are ignored by See Sailing.
Provided CSV is not in one of the recognised formats (B&G Hercules or Triton) See sailing cannot read arbitrary CSV files and is written around just these two formats. Having said that, if you have a Hercules or Triton file that is not working, please send it to me and I'll work the problem.
Warnings are more for your information if you're investigating an issue with your configuration, they may safely be ignored otherwise.
AttitudeData: ignored because not sourced from compass More than one source of attitude data was found. In these cases we assume the attitude data sourced from the compass is to be used and other sources (such as a depth sounder) are ignored.