Index: DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/IoSurfacePoint.cs
===================================================================
diff -u -r3117 -r3135
--- DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/IoSurfacePoint.cs	(.../IoSurfacePoint.cs)	(revision 3117)
+++ DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/IoSurfacePoint.cs	(.../IoSurfacePoint.cs)	(revision 3135)
@@ -23,6 +23,8 @@
 {
     public class IoSurfacePoint
     {
-        
+        public double X { get; set; }
+
+        public double Y { get; set; }
     }
 }
\ No newline at end of file
Index: DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io.Tests/IoDamMStabDocSeriliazerTests.cs
===================================================================
diff -u -r3132 -r3135
--- DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io.Tests/IoDamMStabDocSeriliazerTests.cs	(.../IoDamMStabDocSeriliazerTests.cs)	(revision 3132)
+++ DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io.Tests/IoDamMStabDocSeriliazerTests.cs	(.../IoDamMStabDocSeriliazerTests.cs)	(revision 3135)
@@ -70,7 +70,36 @@
             ioMStabDamDoc.MStabInput.Model.ShearStrength = ShearStrengthType.CPhi;
 
             // SurfaceLine
-
+            ioMStabDamDoc.MStabInput.SurfaceLine.Add(new IoSurfacePoint()
+            {
+                X = 1.0,
+                Y = 1.5
+            });
+            ioMStabDamDoc.MStabInput.SurfaceLine.Add(new IoSurfacePoint()
+            {
+                X = 3.0,
+                Y = 1.5
+            });
+            ioMStabDamDoc.MStabInput.SurfaceLine.Add(new IoSurfacePoint()
+            {
+                X = 5.0,
+                Y = 2.5
+            });
+            ioMStabDamDoc.MStabInput.SurfaceLine.Add(new IoSurfacePoint()
+            {
+                X = 7.0,
+                Y = 2.5
+            });
+            ioMStabDamDoc.MStabInput.SurfaceLine.Add(new IoSurfacePoint()
+            {
+                X = 10.0,
+                Y = 0.5
+            });
+            ioMStabDamDoc.MStabInput.SurfaceLine.Add(new IoSurfacePoint()
+            {
+                X = 15.0,
+                Y = 0.5
+            });
             // Characteristic Points
 
             return ioMStabDamDoc;
Index: DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/FillXmlDamMStabDocFromIo.cs
===================================================================
diff -u -r3132 -r3135
--- DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/FillXmlDamMStabDocFromIo.cs	(.../FillXmlDamMStabDocFromIo.cs)	(revision 3132)
+++ DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/FillXmlDamMStabDocFromIo.cs	(.../FillXmlDamMStabDocFromIo.cs)	(revision 3135)
@@ -19,6 +19,8 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System.Collections.Generic;
+
 namespace Deltares.LayerOnSlopeTool.Io
 {
     public static class FillXmlDamMStabDocFromIo
@@ -36,9 +38,25 @@
 
             xmlDamMStabDoc.tnsPrefixDamMStabInput.tnsbPrefixModel = new tnsbPrefixModel();
             TransferModel(ioDamMStabDamDoc.MStabInput.Model, xmlDamMStabDoc.tnsPrefixDamMStabInput.tnsbPrefixModel);
+
+            xmlDamMStabDoc.tnsPrefixDamMStabInput.tnsbPrefixSurfaceLine = new tnsbPrefixSurfaceLineTnsbPrefixSurfacePoint[ioDamMStabDamDoc.MStabInput.SurfaceLine.Count];
+            TransferSurfaceline(ioDamMStabDamDoc.MStabInput.SurfaceLine, xmlDamMStabDoc.tnsPrefixDamMStabInput.tnsbPrefixSurfaceLine);
+
             return xmlDamMStabDoc;
         }
 
+        private static void TransferSurfaceline(List<IoSurfacePoint> ioSurfaceLine, tnsbPrefixSurfaceLineTnsbPrefixSurfacePoint[] xmlSurfaceLine)
+        {
+            for (int i = 0; i < ioSurfaceLine.Count; i++)
+            {
+                xmlSurfaceLine[i] = new tnsbPrefixSurfaceLineTnsbPrefixSurfacePoint()
+                {
+                    XCoord = ioSurfaceLine[i].X,
+                    YCoord = ioSurfaceLine[i].Y
+                };
+            }
+        }
+
         private static void TransferModel(IoModel ioModel, tnsbPrefixModel xmlModel)
         {
             xmlModel.CalculationModel = ioModel.CalculationModel;
Index: DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/FillIoDamMStabDocFromXml.cs
===================================================================
diff -u -r3132 -r3135
--- DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/FillIoDamMStabDocFromXml.cs	(.../FillIoDamMStabDocFromXml.cs)	(revision 3132)
+++ DamTools/LayerOnSlopeTool/trunk/src/Deltares.LayerOnSlopeTool.Io/FillIoDamMStabDocFromXml.cs	(.../FillIoDamMStabDocFromXml.cs)	(revision 3135)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System.Collections.Generic;
 using System.Net.Http.Headers;
 
 namespace Deltares.LayerOnSlopeTool.Io
@@ -33,9 +34,22 @@
             var ioMStabDamDoc = new IoMStabDamDoc();
             TransferGeometryCreationOptions(xmlDamMStabDamDoc.tnsPrefixDamMStabInput.tnsbPrefixGeometryCreationOptions, ioMStabDamDoc.MStabInput.GeometryCreationOptions);
             TransferModel(xmlDamMStabDamDoc.tnsPrefixDamMStabInput.tnsbPrefixModel, ioMStabDamDoc.MStabInput.Model);
+            TransferSurfaceLine(xmlDamMStabDamDoc.tnsPrefixDamMStabInput.tnsbPrefixSurfaceLine, ioMStabDamDoc.MStabInput.SurfaceLine);
             return ioMStabDamDoc;
         }
 
+        private static void TransferSurfaceLine(tnsbPrefixSurfaceLineTnsbPrefixSurfacePoint[] xmlSurfaceLine, List<IoSurfacePoint> ioSurfaceLine)
+        {
+            for (int i = 0; i < xmlSurfaceLine.Length; i++)
+            {
+                ioSurfaceLine.Add(new IoSurfacePoint()
+                {
+                    X = xmlSurfaceLine[i].XCoord,
+                    Y = xmlSurfaceLine[i].YCoord
+                });
+            }
+        }
+
         private static void TransferModel(tnsbPrefixModel xmlModel, IoModel ioModel)
         {
             ioModel.CalculationModel = xmlModel.CalculationModel;