The axes are displayed in whatever units the plot is in. If you are in UTM-zone 31 in the North Sea, axes will display UTM-coordinates in meters. So - if you are plotting a large area, your axes increment should be set to e.g. 50000 or 100000.
Select something appropriate as increment on the axes. Then press the action button Run plot or Draft Run and your plot will be generated in no time. Note that Geocap is set to 2D mode when plotting. Open the PostScriptfile in a viewer e.g. GhostView and look at the plot. At this point you may also introduce the "Use Gray Frame", activated from the Initiate Plot Panel. Toggle the option "Gray frame around plot and also "Extend grayframe - Length in cm:" and set the length to 6. Rerun and have a look at the plot. Remember to press the "Save Saveset" now and then to save your work.
The Axes and Frame Panel