Topo AND contours

Hello,

I really don't know how to make Basecamp display two maps at the same time - and seemingly that's what my topographic map and its contours are about. When I open the Maps menue I can choose only one "map" at a time which makes it impossible to display altitude contours.

I found the topographic map here: http://garmin.opentopomap.org/

There is a tool to combine both: http://www.gmaptool.eu/en/content/gmaptool
I came across your post because I am just having the same issue. I haven't tried it yet but it seems pretty straightforward. I have both the OSM and the Open Topo map, they look very nice in full detail.

Not sure that will combine maps that overlap into one, it's aimed I think at joining adjoining maps into one.

That's a completely different issue. This thread is about duplicate maps showing in BaseCamp, that simply isn't possible. Overlays are different.

That’s true, and then the same user was discouraged from doing so on the device, and it was claimed the maps must be illegal, which is simply not true:
"All of those programs that create overlay maps are not ones developed by Garmin, nor approved by Garmin. They are all technically illegal. The whole (incorrect) use of the word "transparent" came from the the guy that reverse engineered the map format and wrote cgpsmapper”.

AND

People that (illegally) reverse engineered the programming of the maps figured out that it would work on the GPS in certain ways."

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Garmin official tools can, and do produce transparent maps. It might be that Garmin use the word “overlay" but it’s the same intention.

For unofficial stuff, GPS map edit can combine two maps of the same area, and export to a single img file that can also be displayed in Mapsource or Basecamp,
so long as the source files are open source types (not Garmin NT to begin with etc.) There is a size limitation for the maps the program works with for the free version,
but it does work for free with typical tiles.

Hi. (I hope I am not hijacking this thread). I am a very small step away from being a complete Newbie, so please be gentle. I have a 64S. I purchased two map files: NA City Navigator and a TOPO map. Each map (separately) works fine on the 64S. The problem is that I want to be able to see both maps concurrently so that I can navigate to trailheads (using the City Nav map) and hike the backcountry (using the TOPO map). Please correct me if I am mistaken, but I don't think I can have 2 gmapsupp.img files concurrently on my device. Assuming I am correct about that, I used GMAPTool to join these two map files into one, I think, successfully. Problem now is the file is > 12GB, which is too large for the device (but not the SD card which I installed on the 64s). Can someone provide me guidance (in a way a Newbie can understand) on how I can see both maps concurrently on my device. Thank you for your assistance.

Problem now is the file is > 12GB, which is too large for the device (but not the SD card which I installed on the 64s).

You can split the map into subregions.

Can someone provide me guidance (in a way a Newbie can understand) on how I can see both maps concurrently on my device. Thank you for your assistance.

You can't.

One problem is there are two images and there is no way to have the Garmin use one or another.


The other issue is that the maps both have routing data (I believe) and there is no way to have the Garmin use one or another.

You can create overlay (transparent) maps which add a small amount of image data and which don't have routing information.

That's one way to get contour.

Simply turn on the map you want to use and then switch when needed. The easiest way is with profiles. Have a driving profile with CNNA and a hiking profile with the topo map.

There are ways to combine maps, but they are complex. In addition, CNNA is locked, so that would not be possible with hacking through the encryption. As above, the only real way is an overlay map with contours. This needs to be created in just the right way to make it work.

Thanks for the responses and stopping me from pursuing a dead-end by joining the two maps. The approach I've taken now is to keep the two maps separate and follow Red90rover's suggestion. I now store the NA City Navigator map on the device's internal storage and a somewhat reduced Topo map (using GMAPTools) stored on the SD card. That way I can name both maps "gmapsupp.img". It seems to me that for the 64s to display the map, the map(s) must be named "gmapsupp.img". This naming restriction doesn't seem to apply to BaseCamp where I could call them "gmapsupp-CNNA.img" and "gmapsupp-Topo.img" and store them in the same location. It appears that just because BaseCamp can find and display the mapping data doesn't mean that the device will be able to. Are my assumptions correct? Thank you.

That is not correct. You can give the map any name with an extinction of .img and put them in the Garmin directory on your gps or the sd card. I like to keep them on the sd card but either place will work. I’m using my 64s as an example as that’s what you have but I do the same on my other Garmin handhelds currently it has gmapbmap.img on the gps and on the sd card it has gmapsupp_bike.img, gmapsupp_Gen_New.img, mitopo11.img and NE USA Topo Part 1.img. This is the file names that I changed them to with Windows File Explorer, Basecamp will use the imbedded name so as an example gmapsupp_bike.img will show up as “Openfietsmap Lite (US-MI_06-08-2017)” in Basecamp. I will add other maps as I travel out of state changing the name to something that makes sense to me so I know which ones to delete when I get home.