If map layers disappear or are in the wrong location after changing the coordinate system for the map in Surfer, most likely the map layer that disappeared did not have a coordinate system set for it, or it was set incorrectly. The coordinate system for each map layer must be set as the coordinate system used to create the data, grid, or base map file. The coordinate system that is used to display the data is defined only for the Map object in Surfer.
Please see the article How can I use different coordinate systems in the same Surfer map? for additional information about how to define the proper coordinate systems for each map layer and the final map display.
Updated October 31, 2018