For example:

ContourLayer.LabelTolerance = 8
ContourLayer.LabelLabelDist = 0.5
ContourLayer.LabelEdgeDist = 0.75
ContourLayer.LabelFormat.Type=srfLabFixed
ContourLayer.LabelFormat.NumDigits = 2
ContourLayer.OrientLabelsUphill = True
ContourLayer.LabelFont.Face = "Arial"
ContourLayer.LabelFont.Size = 8

A more detailed example can be found in the attached script, ContourMap.bas, which can also be found in the \Samples\Scripts\ folder in the Surfer installation directory.

See How can I change the label properties for my contour map in Surfer? for instructions on how to edit the properties of contour map labels via the user interface in Surfer.

Updated November 2021