[SailorTom]

Problems with COG update rate:
I find the COG when on a steady course in flat water varies by around +/-15deg.
This I assume could be caused by
gps accuracy
Refresh rate
?
I have been using iNavx for racing around the cans. I use an ipad mini2, cellular, but haven't bothered putting a SIM in it yet.
Possible solutions
Software fix in some setting in ipad
INav config
Put SIM in it, so it uses cellular
External GPS
??

Haging spent this much, not too worried about cost, need to get it done to do my tacticians role!

Any suggestions greatfully recieved!!

[GPSNavX]

What I would look at is the "HPE:" field to see what the accuracy of the GPS is. If it's greater than 32' you probably won't get an accurate COG. Also make sure the "UTC:" field is updating every second or so. Both require the iPad/iPhone have a clear shot to the sky.