diff --git a/src/Mod/Path/PathScripts/PathWaterline.py b/src/Mod/Path/PathScripts/PathWaterline.py
index 98465b0171..060bde9b19 100644
--- a/src/Mod/Path/PathScripts/PathWaterline.py
+++ b/src/Mod/Path/PathScripts/PathWaterline.py
@@ -406,6 +406,31 @@ class ObjectWaterline(PathOp.ObjectOp):
             obj.AvoidLastX_Faces = 100
             PathLog.error(translate('PathWaterline', 'AvoidLastX_Faces: Avoid last X faces count limited to 100.'))
 
+    def opUpdateDepths(self, obj):
+        if hasattr(obj, 'Base') and obj.Base:
+            base, sublist = obj.Base[0]
+            fbb = base.Shape.getElement(sublist[0]).BoundBox
+            zmin = fbb.ZMax
+            for base, sublist in obj.Base:
+                for sub in sublist:
+                    try:
+                        fbb = base.Shape.getElement(sub).BoundBox
+                        zmin = min(zmin, fbb.ZMin)
+                    except Part.OCCError as e:
+                        PathLog.error(e)
+            obj.OpFinalDepth = zmin
+        elif self.job:
+            if hasattr(obj, 'BoundBox'):
+                if obj.BoundBox == 'BaseBoundBox':
+                    models = self.job.Model.Group
+                    zmin = models[0].Shape.BoundBox.ZMin
+                    for M in models:
+                        zmin = min(zmin, M.Shape.BoundBox.ZMin)
+                    obj.OpFinalDepth = zmin
+                if obj.BoundBox == 'Stock':
+                    models = self.job.Stock
+                    obj.OpFinalDepth = self.job.Stock.Shape.BoundBox.ZMin
+
     def opExecute(self, obj):
         '''opExecute(obj) ... process surface operation'''
         PathLog.track()