BoatBanter.com - navionics mmc question

thanks, that does explain how it works.

"Gary" wrote in message
...
Navionics chart in MMC media? You must have a Lowrance GPS. I wondered
about the same thing. I hate leaving high value MMC charts in the boat.
Fortunately the Lowrance chart plotters are not as popular as the other
makes, so theft is not a pervasive problem.

I used to be able copy chart files from MMC to disk drive by using an
old version of the Lowrance MMC reader software, but the file has zero
value as a backup. I'm not sure, but I think later Lowrance software
updates removed the ability to copy the files at all.

Apparently the Navionics charts have a unique file storage "format."
File format as in "formatting" the media for first time use - it's
different from the DOS file format. Lowrance chart plotter software can
read files in the proprietary format, but apparently cannot re-format an
MMC in the proprietary Navionics format, nor write files to MMC in that
format. It seems that only Navionics is able to perform the necessary
initial formatting. Hence the cautions to never reformat a Navionics MMC
using the Lowrance utilities. You would have a DOS-formatted MMC (as
used with the MapCreate charts) and need to buy a new chart.

BTW www.landfallnavigation.com used to have the lowest price on the
charts, but I don't know if that's still true.