Reshape/edit individual contour lines in Surfer

In Surfer 14 and newer versions, you can follow the instructions here to edit your grid in the grid editor window, thereby changing the contour lines: Edit a grid file in Surfer. Alternatively, you can follow the instructions below to export the contours to a vector file, plot the vector file as a base map, reshape the contour lines, and then convert back to a contour map:

1. Select the contours and click Map Tools | Layer Tools | Export Contours.
2. Choose to save it in an AutoCAD DXF file, give the file a name, and click Save.
3. Click Home | Add to Map | Layer | Base, select the DXF file and click Open.
4. Click OK in the DXF Import Options dialog. The base layer of the contours is added to the original map.
5. Click the + icon next to the Base(vector) layer to expand the layer and view all polylines/polygons within the layer. Each has a ZLEVEL attribute equal to the Z value of that contour line. You can see the attributes by selecting an object and clicking the Info tab in the Properties window.
6. Uncheck the check box next to the Contours layer in the Contents window so you no longer see the contour map.
7. Select the polyline/polygon in the Base layer to be reshaped and click Features | Edit Feature | Reshape to display the vertices of the object.
8. Reshape the selected contour.
9. Repeat steps 8 and 9 for any other contours to be reshaped. When you're done reshaping, press ESC on your keyboard to exit Reshape mode. 
10. To add additional contour lines, click Features | Insert | Polyline or Polygon, then draw the contour on the map, double clicking the last point to finalize the object. 
11. Press ESC when you're done drawing new contours to exit drawing mode.
12. Right click on the Base(vector) layer in the Contents window and click Open Attribute Table.
13. Move the Attribute Table off to the side of your map. 
14. Click in one of the empty ZLEVEL cells. The associated shape will be selected on the map. Enter the appropriate contour level value for that ZLEVEL into the Attribute Table. 
15. Repeat for all contours you added, closing the Attribute Table when you're done. 
16. Click Grids | New Grid | Grid from Contours.
17. In the Grid Contours dialog, select your base layer from the Contour Source list.
18. In the Select Field dialog, choose ZLEVEL from the list, then click OK.
19. In the Output Grid section, give your grid file a name.
20. Change the New layer type to Contour.
21. Set any other desired options, then click OK. A new map is created with a contour layer based on the grid from your vector file.

Please contact us if you would like to add your vote to our suggestion file for a way to reshape contour level lines.