Surfer uses coordinates that increase in the X and Y directions. There is not a way to center a map on 180°/-180°.
To work around this, you can :
- Create two maps. One for the left side, from 0° to 180°, and another for the right side from -180° to 0. Then use the Layout | Arrange | Align commands to arrange them so they line up. You should not overlay them, since that will move them back.
- Add 360 to the X coordinate.
- Use a file like Pacificp.gsb (attached) to display the base map with positive coordinates from -30 to 360.
Pacificp.gsb base map in Surfer.
Pacificp.gsb base map converted to Mercator projection.
Updated February 10, 2017