diff --git a/samples/blackmiscquantities/samplesgeo.cpp b/samples/blackmiscquantities/samplesgeo.cpp
index 96494c978..4a00cc6d0 100644
--- a/samples/blackmiscquantities/samplesgeo.cpp
+++ b/samples/blackmiscquantities/samplesgeo.cpp
@@ -66,9 +66,18 @@ namespace BlackSample
         CCoordinateGeodetic geo2(geoVector);
         deltaLat = geo2.latitude() - lat;
         deltaLng = geo2.longitude() - lng;
-
         out << deltaLat.valueRoundedWithUnit(digits) << " " << deltaLng.valueRoundedWithUnit(digits) << endl;
 
+        // Heading/bearing of same values
+        CAngle bearing = geo.calculateBearing(geo);
+        CLength distance = geo.calculateGreatCircleDistance(geo);
+        out << bearing.valueRoundedWithUnit(CAngleUnit::deg(), 2) << " " << distance.valueRoundedWithUnit(CLengthUnit::m(), 2) << endl;
+
+        const CCoordinateGeodetic nullCoordinate;
+        bearing = geo.calculateBearing(nullCoordinate);
+        distance = geo.calculateGreatCircleDistance(nullCoordinate);
+        out << bearing.valueRoundedWithUnit(CAngleUnit::deg(), 2) << " " << distance.valueRoundedWithUnit(CLengthUnit::m(), 2) << endl;
+
         // bye
         out << "-----------------------------------------------" << endl;
         return 0;
diff --git a/src/blackmisc/geo/coordinategeodetic.cpp b/src/blackmisc/geo/coordinategeodetic.cpp
index c8a90ffba..98ee0520c 100644
--- a/src/blackmisc/geo/coordinategeodetic.cpp
+++ b/src/blackmisc/geo/coordinategeodetic.cpp
@@ -43,6 +43,7 @@ namespace BlackMisc
         CLength calculateGreatCircleDistance(const ICoordinateGeodetic &coordinate1, const ICoordinateGeodetic &coordinate2)
         {
             if (coordinate1.isNull() || coordinate2.isNull()) { return CLength::null(); }
+            // if (coordinate1.equalNormalVectorDouble(coordinate2)) { return CLength(0, CLengthUnit::defaultUnit()); }
             static const float earthRadiusMeters = 6371000.8f;
             const QVector3D v1 = coordinate1.normalVector();
             const QVector3D v2 = coordinate2.normalVector();
@@ -53,6 +54,7 @@ namespace BlackMisc
         CAngle calculateBearing(const ICoordinateGeodetic &coordinate1, const ICoordinateGeodetic &coordinate2)
         {
             if (coordinate1.isNull() || coordinate2.isNull()) { return CAngle::null(); }
+            // if (coordinate1.equalNormalVectorDouble(coordinate2)) { return CAngle(0, CAngleUnit::defaultUnit()); } // null or 0?
             static const QVector3D northPole { 0, 0, 1 };
             const QVector3D c1 = QVector3D::crossProduct(coordinate1.normalVector(), coordinate2.normalVector());
             const QVector3D c2 = QVector3D::crossProduct(coordinate1.normalVector(), northPole);