GGU-3D-SSFLOW: "Depths in section" menu item
After defining a quadrilateral, all nodes within it can be assigned new depths. Select the action required from the following dialog box:

"Assign default depths"
The default depths are assigned. This alters the depths at the selected node for all planes."Raise active plane by dz"
The depths of the selected nodes are raised by the value dz given for the active plane."Set active plane to z"
The depths of the selected nodes are set to the depth z given for the active plane.