Actually, the masthead position is above the content for all the layouts.
so it appears always up, for the customization in the masthead module, it took more time consuming and testing as it need customization in module file to add map feature.
If you want to show the map you can do it, unpublish the masthead module and use your module in custom HTML code. Publish it masthead position.
In the template, we used JA Google map plugin: http://prntscr.com/heia2p
You have to select the location and copy the code to use this in custom html module.
Let me know with screenshot details if you are trying to something different.