Installing a OSM map on Mac (BaseCamp)

Hi everybody,

I’m quite new in using OSM.
Times ago I managed to downloag the OSM French Guyana map on my Garmin 60CSX. And it works perfectly.

I have bought a new MacPro computer (and I’m not yet familiar with Macs, I must say). I have installed the BaseCamp app. on it.

I requested a OSM French Guyana map on the website. I received the e-mail with the 4 different files.

I downloaded the file on my computer.
When I extract it, I don’t see any executable file, only a folder named “OSM generic routable(GUF_13-08-2015).gmap” that contains various non executable files.

So my question is: where is the installer? I guess it should be an executable file but I don’t see any.

I’m a bit lost.

Can anyone of you help me?



You need:


For great maps also look here:




I have been using OSM for a while. I am using Basecamp on a Mac with OSX 10.10.5. I am sure that when I used to download a map from OSM.NL i would simply double click it and it would install itself, but now there is no executable file. Am i mis-remembering or being a bit thick?

I have tried the advice above with Javawa map convertor but when i drop the .zip file into to it to convert it says "This folder does not contains a .img file with overview map?

Can anyone help please?

You should use the other tool, called gmtk.
The download file from the garmin site ( should be expanded. What you get is a file with an extension of .gmap (or .gmapi).

There is a menu option Extra, it gives you the option to select any .gmap or .gmapi file and transfer that to the correct location for Basecamp (use the default!)

If the gmap file looks like a folder instead like a single file, the bundle-bit is not set and gmtk cannot find it! If you have Pathfinder installed as your filemanager (instead of the Finder) you can set the bundlebit with it. Otherwise google…

Finally, the most simple method is to go to your user library (in the Finder use Go…) then to Application Support then to Garmin then to Maps:

**User/Your Username Here/Library/Application Support/Garmin/Maps

Drop the gmap file (or folder) into this location and your all set.

Hi Marc

Thanks for this. When I unzip OSM Generic Routable.gmap my .gmap file is a folder not a file. I have googled bundlebit’ing but this is beyond my skills! So I have dropped the whole GMAP folder into the location - Still didn’t want to appear so also delete the last OSM Generic map that I had not renamed and it now appears.

Thanks for your help.