diff --git a/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/scalablevalue/impl/ScalablePosition.java b/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/scalablevalue/impl/ScalablePosition.java
index 2d0ed6be94c..6115de11082 100755
--- a/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/scalablevalue/impl/ScalablePosition.java
+++ b/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/scalablevalue/impl/ScalablePosition.java
@@ -14,7 +14,7 @@ public class ScalablePosition implements ScalableValueWithDistance<ScalablePosit
                 Math.sin(position.getLatRad()));
     }
     
-    public ScalablePosition(double x, double y, double z) {
+    private ScalablePosition(double x, double y, double z) {
         this.x = x;
         this.y = y;
         this.z = z;
diff --git a/java/com.sap.sailing.polars.test/src/com/sap/sailing/polars/windestimation/test/TestWindEstimationFromManeuversOnAFew505Races.java b/java/com.sap.sailing.polars.test/src/com/sap/sailing/polars/windestimation/TestWindEstimationFromManeuversOnAFew505Races.java
similarity index 62%
rename from java/com.sap.sailing.polars.test/src/com/sap/sailing/polars/windestimation/test/TestWindEstimationFromManeuversOnAFew505Races.java
rename to java/com.sap.sailing.polars.test/src/com/sap/sailing/polars/windestimation/TestWindEstimationFromManeuversOnAFew505Races.java
index e4e19ec6fff..17f7f06e625 100755
--- a/java/com.sap.sailing.polars.test/src/com/sap/sailing/polars/windestimation/test/TestWindEstimationFromManeuversOnAFew505Races.java
+++ b/java/com.sap.sailing.polars.test/src/com/sap/sailing/polars/windestimation/TestWindEstimationFromManeuversOnAFew505Races.java
@@ -1,4 +1,4 @@
-package com.sap.sailing.polars.windestimation.test;
+package com.sap.sailing.polars.windestimation;
 
 import static org.junit.Assert.assertEquals;
 
@@ -9,18 +9,31 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.text.ParseException;
+import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.Executors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
 
 import org.junit.Ignore;
 import org.junit.Test;
 
+import com.sap.sailing.domain.base.Competitor;
+import com.sap.sailing.domain.common.Bearing;
+import com.sap.sailing.domain.common.confidence.impl.ScalableDouble;
+import com.sap.sailing.domain.common.impl.DegreeBearingImpl;
+import com.sap.sailing.domain.common.scalablevalue.impl.ScalableBearing;
 import com.sap.sailing.domain.test.OnlineTracTracBasedTest;
+import com.sap.sailing.domain.tracking.Maneuver;
 import com.sap.sailing.domain.tracking.Wind;
 import com.sap.sailing.domain.tracking.impl.ScalableWind;
 import com.sap.sailing.domain.tractracadapter.ReceiverType;
 import com.sap.sailing.polars.impl.PolarDataServiceImpl;
 import com.sap.sailing.polars.regression.NotEnoughDataHasBeenAddedException;
-import com.sap.sailing.polars.windestimation.ManeuverBasedWindEstimationTrackImpl;
+import com.sap.sailing.polars.windestimation.ManeuverBasedWindEstimationTrackImpl.ManeuverClassification;
+import com.sap.sse.common.Util.Pair;
+import com.sap.sse.util.kmeans.Cluster;
+import com.sap.sse.util.kmeans.KMeansMappingClusterer;
 import com.tractrac.model.lib.api.event.CreateModelException;
 import com.tractrac.subscription.lib.api.SubscriberInitializationException;
 
@@ -67,6 +80,28 @@ public class TestWindEstimationFromManeuversOnAFew505Races extends OnlineTracTra
         Wind average = getManeuverBasedAverageWind();
         assertEquals(275, average.getFrom().getDegrees(), 5.0); // wind in this race was from 075deg on average
     }
+    
+    @Test
+    public void testTwoDimensionalClustering() throws NotEnoughDataHasBeenAddedException, MalformedURLException,
+            IOException, InterruptedException, URISyntaxException, ParseException, SubscriberInitializationException,
+            CreateModelException {
+        setUp("event_20110609_KielerWoch-505_Race_3");
+        ManeuverBasedWindEstimationTrackImpl windTrack = new ManeuverBasedWindEstimationTrackImpl(new PolarDataServiceImpl(Executors.newFixedThreadPool(4)),
+                getTrackedRace(), /* millisecondsOverWhichToAverage */ 30000, /* waitForLatest */ true);
+        final Map<Maneuver, Competitor> maneuvers = windTrack.getAllManeuvers(/* waitForLatest */ true);
+        final int numberOfClusters = 16;
+        KMeansMappingClusterer<ManeuverClassification, Pair<ScalableBearing, ScalableDouble>, Pair<Bearing, Double>, ScalableBearingAndScalableDouble> clusterer =
+                new KMeansMappingClusterer<>(numberOfClusters,
+                        windTrack.getManeuverClassifications(maneuvers),
+                        (mc)->new ScalableBearingAndScalableDouble(mc.getMiddleManeuverCourse(), mc.getManeuverAngleDeg()), // maps maneuver classification to cluster metric
+                        // use an evenly distributed set of cluster seeds for clustering wind direction estimations
+                        Stream.concat(IntStream.range(0, numberOfClusters/2).mapToObj((i)->
+                            new Pair<>(new DegreeBearingImpl(((double) i)*360./(double) numberOfClusters/2), 45.)),
+                            IntStream.range(0, numberOfClusters/2).mapToObj((i)->
+                                new Pair<>(new DegreeBearingImpl(((double) i)*360./(double) numberOfClusters/2), -45.))));
+        final Set<Cluster<ManeuverClassification, Pair<ScalableBearing, ScalableDouble>, Pair<Bearing, Double>, ScalableBearingAndScalableDouble>> clusters = clusterer.getClusters();
+        assertEquals(8, clusters.size());
+    }
 
     private Wind getManeuverBasedAverageWind() throws NotEnoughDataHasBeenAddedException {
         ManeuverBasedWindEstimationTrackImpl windTrack = new ManeuverBasedWindEstimationTrackImpl(new PolarDataServiceImpl(Executors.newFixedThreadPool(4)),
diff --git a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ManeuverBasedWindEstimationTrackImpl.java b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ManeuverBasedWindEstimationTrackImpl.java
index 0e7c5a2830b..ad0c3eb2529 100755
--- a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ManeuverBasedWindEstimationTrackImpl.java
+++ b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ManeuverBasedWindEstimationTrackImpl.java
@@ -454,12 +454,15 @@ public class ManeuverBasedWindEstimationTrackImpl extends WindTrackImpl {
     /**
      * For each maneuver from <code>maneuvers</code>, a {@link ManeuverClassification object} is created.
      */
-    private Stream<ManeuverClassification> getManeuverClassifications(final Map<Maneuver, Competitor> maneuvers) {
+    Stream<ManeuverClassification> getManeuverClassifications(final Map<Maneuver, Competitor> maneuvers) {
         return maneuvers.entrySet().stream().map((maneuverAndCompetitor)->
             new ManeuverClassification(maneuverAndCompetitor.getValue(), maneuverAndCompetitor.getKey()));
     }
 
-    private Map<Maneuver, Competitor> getAllManeuvers(boolean waitForLatest) {
+    /**
+     * Package scope to let test fragment access it
+     */
+    Map<Maneuver, Competitor> getAllManeuvers(boolean waitForLatest) {
         Map<Maneuver, Competitor> maneuvers = new HashMap<>();
         final Waypoint firstWaypoint = trackedRace.getRace().getCourse().getFirstWaypoint();
         final Waypoint lastWaypoint = trackedRace.getRace().getCourse().getLastWaypoint();
diff --git a/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ScalableBearingAndScalableDouble.java b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ScalableBearingAndScalableDouble.java
new file mode 100755
index 00000000000..13b26e4dc2b
--- /dev/null
+++ b/java/com.sap.sailing.polars/src/com/sap/sailing/polars/windestimation/ScalableBearingAndScalableDouble.java
@@ -0,0 +1,61 @@
+package com.sap.sailing.polars.windestimation;
+
+import com.sap.sailing.domain.common.Bearing;
+import com.sap.sailing.domain.common.confidence.impl.ScalableDouble;
+import com.sap.sailing.domain.common.scalablevalue.impl.ScalableBearing;
+import com.sap.sse.common.Util.Pair;
+import com.sap.sse.common.scalablevalue.ScalableValue;
+import com.sap.sse.common.scalablevalue.ScalableValueWithDistance;
+
+/**
+ * Two {@link Bearings} combined in one scalable object, like a vector of two bearings. {@link #add(ScalableValue)
+ * Addition} works component wise, and so does {@link #multiply(double) multiplication} and {@link #divide(double)
+ * division}. The {@link #getDistance(Pair) distance} is calculated as the Euklidian two-dimensional distance between
+ * the two bearing pairs, with "degrees" as conceptual unit. For example, another object of this type that is 2 and 3 degrees
+ * apart from this object will have a distance of {@link Math#sqrt(double) Math.sqrt(13)}.
+ * 
+ * @author Axel Uhl (D043530)
+ *
+ */
+public class ScalableBearingAndScalableDouble implements
+        ScalableValueWithDistance<Pair<ScalableBearing, ScalableDouble>, Pair<Bearing, Double>> {
+    private final ScalableBearing b1;
+    private final ScalableDouble  b2;
+
+    public ScalableBearingAndScalableDouble(Bearing b1, double b2) {
+        this(new ScalableBearing(b1), new ScalableDouble(b2));
+    }
+    
+    private ScalableBearingAndScalableDouble(ScalableBearing b1, ScalableDouble b2) {
+        super();
+        this.b1 = b1;
+        this.b2 = b2;
+    }
+
+    @Override
+    public Pair<Bearing, Double> divide(double divisor) {
+        return new Pair<>(b1.divide(divisor), b2.divide(divisor));
+    }
+
+    @Override
+    public Pair<ScalableBearing, ScalableDouble> getValue() {
+        return new Pair<>(b1, b2);
+    }
+
+    @Override
+    public double getDistance(Pair<Bearing, Double> other) {
+        final double b1DiffDeg = b1.divide(1).getDifferenceTo(other.getA()).getDegrees();
+        final double b2DiffDeg = Math.abs(b2.divide(1)-other.getB());
+        return Math.sqrt(b1DiffDeg*b1DiffDeg + b2DiffDeg*b2DiffDeg);
+    }
+
+    @Override
+    public ScalableBearingAndScalableDouble add(ScalableValue<Pair<ScalableBearing, ScalableDouble>, Pair<Bearing, Double>> t) {
+        return new ScalableBearingAndScalableDouble(b1.add(t.getValue().getA()), b2.add(t.getValue().getB()));
+    }
+
+    @Override
+    public ScalableBearingAndScalableDouble multiply(double factor) {
+        return new ScalableBearingAndScalableDouble(b1.multiply(factor), b2.multiply(factor));
+    }
+}
diff --git a/java/com.sap.sse/src/com/sap/sse/util/kmeans/Cluster.java b/java/com.sap.sse/src/com/sap/sse/util/kmeans/Cluster.java
index a2d280f62c8..b383b62be8d 100755
--- a/java/com.sap.sse/src/com/sap/sse/util/kmeans/Cluster.java
+++ b/java/com.sap.sse/src/com/sap/sse/util/kmeans/Cluster.java
@@ -115,7 +115,11 @@ public class Cluster<E, ValueType, AveragesTo, T extends ScalableValueWithDistan
     
     @Override
     public String toString() {
-        return "{mean: "+getMean()+", centroid: "+getCentroid()+", elements: "+elements+"}";
+        return "{mean: "+getMean()+", centroid: "+getCentroid()+", size: "+size()+", variance: "+getVariance()+", elements: "+elements+"}";
+    }
+
+    private double getVariance() {
+        return stream().mapToDouble((e)->getDistanceFromMean(e)*getDistanceFromMean(e)).average().getAsDouble();
     }
 
     public Stream<E> stream() {