[simmsdp]

I have just added a new iPad2 as a chart plotter in the cockpit. The Mac with MacENC is down at the Navigators station. I came into the bay at Tenacatitia, Mexico yesterday and I noticed that the MacENC Navionics charts are off by 1/2 mile where as the iPad Navionics charts were spot on. Our buddy boat has a Raymarine chart plotter with Navionics charts and they didn't see an error.

What is up with the difference? I have the latest versions from XTravers.

Best.
Salty Doug

[svenbeb]

Hy Salty Dog,

do you youse the NMEA Data over TCP form your MacENC or du you use the internal GPS from the ipad?

The internat GPS from the ipad is not exact as a real GPS like a Furuno, so if you use 2 different GPS sources, you can have two positions

I have the same setup and i configured MacENC to transfer the NMEA Data in my WLAN - and the ipad use this data. So i have all the NMEA Data of my instruments on my ipad.

Regards
Sven

[GPSNavX]

Before assuming the charts were "OFF" did you verify that the GPS position: LAT/LON was identical on both the GPS interfaced to the Mac/MacENC and then the iPad 3G/iNavX GPS?

You can also check the chart versions in both MacENC and iNavX to see if they were the same. To do so in MacENC the versions are listed in the Chart Manager, and in iNavX selecting the "i"nfo button in the lower right hand corner will display the version.

Another thing to check is the GPS accuracy. In MacENC, the horizontal position error (HPE) is displayed in the GPS panel Satellites drawer, and in iNavX the HPE is in the Instruments view or banner. Typically I see under 20' for both Mac and iPad 3G. The iPad 3G GPS does not need an internet connection to function accurately.

If you can provide a lat/lon I can verify the Navionics charts for both iNavX and MacENC are in agreement both geographically and version number.

[simmsdp]

Hi,
I was using the Navionics App "Carib&S.America HD" v2.3.1 on the iPad 2 3G, not iNavX.
I have the the waypoints from the iPad and the Garmin 176Cs as I saved them both:
iPad Navionics N19 17.914, W104 50.278
Garmin-MacENC N19 17.91, W104 50.27

The Navionics charts in MacENC plotted me onshore by >1/3 mile when I was anchored in 18' of water. The iPad Navionics charts had me anchored where I thought I should be.

The Chart Manager lists the two charts as follows:
California S - Baja Jan-01-10(901)
Cent America West Jan-05-10(901)

I downloaded these Navionics charts Feb 11, 2011.

I am now in Manzanillo Bay and the MacENC-Navionics charts and the iPad-Navionics charts agree. The two waypoints are:
iPad Navionics N19 06.114, W104 20.688
Garmin-MacENC N19 06.11, W104 20.69

Thanks for your help.

[GPSNavX]

Thanks. I will contact Navionics and see if there is an update to the 3XG region. When an update is available you will receive an email from X-Traverse.

[GPSNavX]

Navionics have updated the 3XG region. This update fixes the problem you found. You will receive an email from X-Traverse, but in the meantime you can download the 3XG region again following these steps ..

http://www.gpsnavx.com/pdf/X-Traverse.pdf