I'll add the gpsvisualizer to the Therion wiki, as it looks like a good way to get a smoothed ground profile over a cave centreline. >Just so I'm clear, did you just upload your therion generated kml file here?

Yes, I used the 'model' version of the .kml file, with the x, y centreline coordinates. For the output, I just copy and pasted from the website text box, added station names in excel and pasted back into therion as fixed stations. The only issue I have noticed is that you seem to get an extra point at the end of the dataset that is back at the start of the path. I think I understand the map & survey structuring a bit better now. Thanks for the links. I can see I need to create a scrap for the surface to make it visible. My structure, albeit non-existent, wasn't the problem! I have used the following process to add the ground profile to both the extended and elevation pdf projections: Export a .kml model of the cave centreline Import to gpsvisualiser to add the ground altitudes to each co-ordinate Create a new centreline survey with fixed stations for this set of lat, long, alt coordinates Export an .xvi of this survey Import the .xvi into therion graphical editor Create a scrap, referencing some of the stations Trace the stations with a line (I have currently used 'walls', but I am open to suggestions for a better line to use?). Include this scrap and the centreline survey in the exported map. Sample work-in-progress here : https://dl.dropboxusercontent.com/u/4064739/draft_extended_04sep2013.pdf From a cave diving perspective, it would be useful to add local zero depth lines using a similar process. Is there an appropriate line type to use for this? Steve