A single 2D, non-rotated map will be exported to an image file in map coordinates if you choose to save the spatial referencing. If you export from a georeferenced Surfer map (i.e. a map with a coordinate system assigned to it) to an image file format and save the spatial reference information, but the image is georeferenced in page units (not map units), it is likely due to one of these reasons:

1. You have more than one map object on the page.
2. You have drawing objects (text, polylines, polygons, points, scale bar, color bar) on the page.
3. The map you are exporting is rotated. 
4. The map you are exporting is a 3D map. 

If situation #1 or #2 above applies to you, you can export your map to map units by doing the following:

1. Click File | Export, choose to export to the image file format you want, and click Save.
2. In the Export Options dialog, click on the Spatial References tab.
3. Set the Coordinate System at the top to the Map whose map units you want to use for the export.
4. Make sure one or more of the spatial reference formats is checked.
5. Click OK and the image is exported with the spatial referencing.

When exporting a file with multiple maps, or with drawn object(s) to a GeoTIFF, set the Coordinate System to the Map with the desired map units.

If situation #3 or #4 above applies to you, then there is not a way to get a georeferenced export. For a rotated map, you can remove the rotation and then export the map. 

1. In the Contents window, click on the Map.
2. Click on the View tab in the Properties window.
3. If not already set to these values, set the Rotation to 0 and the Tilt to 90.
4. If Rotation and Tilt are already 0 and 90 respectively, click Home | Selection | Transform, set the Rotation to 0 in the Transform dialog, and click OK.

Contact surfersupport@goldensoftware.com if you wish to add your vote for to our suggestion file for the ability to export a rotated map with georeferencing. 

Contact surfersupport@goldensoftware.com if you wish to add your vote for to our suggestion file for the ability to export a 3D map with georeferencing. 

Updated October 16, 2018