If you want to check a BlueChart g2 IMG-map on a PC, use Garmin HomePort instead of MapSource. HomePort reads Garmin marine maps located on memory cards attached to a PC with a memory card reader.
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File names like "gmapsupp.img" & "gmapsupp.unl" aren't case sensitive.
More info about Garmin files:
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It should work with a 25-character key based on either UnitID or CardID and MapID (411), PID (1) plus optional RgnID & VenID. Garmin Mobile PC or Garmin Mobile XT section is NOT used for generating a map unlock key.
[Only registered and activated users can see links. ]