diff --git a/java/com.sap.sailing.domain.shared.android.test/src/com/sap/sailing/domain/regattalog/tracking/analyzing/test/CompetitorDeregistrationTest.java b/java/com.sap.sailing.domain.shared.android.test/src/com/sap/sailing/domain/regattalog/tracking/analyzing/test/CompetitorDeregistrationTest.java
new file mode 100755
index 00000000000..693e7df1e24
--- /dev/null
+++ b/java/com.sap.sailing.domain.shared.android.test/src/com/sap/sailing/domain/regattalog/tracking/analyzing/test/CompetitorDeregistrationTest.java
@@ -0,0 +1,37 @@
+package com.sap.sailing.domain.regattalog.tracking.analyzing.test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
+
+import java.util.Collections;
+import java.util.Set;
+
+import org.junit.Test;
+
+import com.sap.sailing.domain.abstractlog.regatta.RegattaLog;
+import com.sap.sailing.domain.abstractlog.regatta.RegattaLogEvent;
+import com.sap.sailing.domain.abstractlog.regatta.RegattaLogEventVisitor;
+import com.sap.sailing.domain.abstractlog.regatta.events.impl.RegattaLogRegisterCompetitorEventImpl;
+import com.sap.sailing.domain.abstractlog.shared.analyzing.CompetitorDeregistrator;
+import com.sap.sailing.domain.abstractlog.shared.analyzing.CompetitorsInLogAnalyzer;
+import com.sap.sailing.domain.base.Competitor;
+import com.sap.sailing.domain.base.impl.CompetitorImpl;
+import com.sap.sse.common.impl.MillisecondsTimePoint;
+
+public class CompetitorDeregistrationTest extends AbstractRegattaLogTrackingTest {
+    private final Competitor competitor = new CompetitorImpl("comp", "Comp", null, null, null, null, null, /* timeOnTimeFactor */ null, /* timeOnDistanceAllowancePerNauticalMile */ null);
+    private final Competitor competitor2 = new CompetitorImpl("comp2", "Comp2", null, null, null, null, null, /* timeOnTimeFactor */ null, /* timeOnDistanceAllowancePerNauticalMile */ null);
+    
+    @Test
+    public void testCompetitorDeregistration() {
+        log.add(new RegattaLogRegisterCompetitorEventImpl(MillisecondsTimePoint.now(), author, competitor));
+        log.add(new RegattaLogRegisterCompetitorEventImpl(MillisecondsTimePoint.now(), author, competitor2));
+        final CompetitorDeregistrator<RegattaLog, RegattaLogEvent, RegattaLogEventVisitor> deregistrator = new CompetitorDeregistrator<>(log,
+                Collections.singleton(competitor2), author);
+        final Set<RegattaLogEvent> events = deregistrator.analyze();
+        deregistrator.deregister(events);
+        final Set<Competitor> competitors = new CompetitorsInLogAnalyzer<>(log).analyze();
+        assertEquals(1, competitors.size());
+        assertSame(competitor, competitors.iterator().next());
+    }
+}
diff --git a/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/abstractlog/shared/analyzing/CompetitorDeregistrator.java b/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/abstractlog/shared/analyzing/CompetitorDeregistrator.java
index f1316b292b4..06c05304b64 100644
--- a/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/abstractlog/shared/analyzing/CompetitorDeregistrator.java
+++ b/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/abstractlog/shared/analyzing/CompetitorDeregistrator.java
@@ -1,6 +1,7 @@
 package com.sap.sailing.domain.abstractlog.shared.analyzing;
 
 import java.util.HashSet;
+import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -14,14 +15,21 @@ import com.sap.sailing.domain.common.abstractlog.NotRevokableException;
 import com.sap.sse.common.Util;
 
 /**
- * Generates events that close the events that are responsible for the {@link #mapping} that is passed to the
- * constructor.
+ * Finds the competitor registration events for a given set of {@link Competitor competitors} that must be
+ * {@link AbstractLog#revokeEvent(AbstractLogEventAuthor, AbstractLogEvent) revoked} in order to deregister the
+ * competitors. Note that the de-registration cannot be performed during analysis because
+ * {@link BaseLogAnalyzer#analyze()} obtains a read lock on the log whereas
+ * {@link AbstractLog#revokeEvent(AbstractLogEventAuthor, AbstractLogEvent)} requires a write lock, and upgrading from a
+ * read to a write lock is not possible.<p>
+ * 
+ * Clients must call {@link #deregister} with the result of {@link #analyze()} in order to actually perform the
+ * deregistration.
  * 
  * @author Jan Bross
  *
  */
 public class CompetitorDeregistrator<LogT extends AbstractLog<EventT, VisitorT>, EventT extends AbstractLogEvent<VisitorT>, VisitorT>
-extends BaseLogAnalyzer<LogT, EventT, VisitorT, Void> {
+extends BaseLogAnalyzer<LogT, EventT, VisitorT, Set<EventT>> {
 
     private static final Logger logger = Logger.getLogger(CompetitorDeregistrator.class.getName());
     protected final Iterable<Competitor> competitorsToDeregister;
@@ -34,24 +42,29 @@ extends BaseLogAnalyzer<LogT, EventT, VisitorT, Void> {
     }
 
     @Override
-    protected Void performAnalysis() {
-        HashSet<Competitor> competitorSet = new HashSet<Competitor>();
+    protected Set<EventT> performAnalysis() {
+        final Set<EventT> result = new HashSet<>();
+        final HashSet<Competitor> competitorSet = new HashSet<Competitor>();
         Util.addAll(competitorsToDeregister, competitorSet);
-        
         for (EventT event : log.getUnrevokedEventsDescending()) {
             if (event instanceof RegisterCompetitorEvent) {
                 RegisterCompetitorEvent<?> registerEvent = (RegisterCompetitorEvent<?>) event;
                 if (competitorSet.contains(registerEvent.getCompetitor())) {
-                    try {
-                        log.revokeEvent(eventAuthor, event,
-                                "unregistering competitor because no longer selected for registration");
-                    } catch (NotRevokableException e) {
-                        logger.log(Level.WARNING, "could not unregister competitor by adding RevokeEvent", e);
-                    }
+                    result.add(event);
                 }
             }
         }
-        
-        return null;
+        return result;
+    }
+    
+    public void deregister(final Set<EventT> competitorRegistrationEvents) {
+        for (final EventT event : competitorRegistrationEvents) {
+            try {
+                log.revokeEvent(eventAuthor, event,
+                        "unregistering competitor because no longer selected for registration");
+            } catch (NotRevokableException e) {
+                logger.log(Level.WARNING, "could not unregister competitor by adding RevokeEvent", e);
+            }
+        }
     }
 }
diff --git a/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/tracking/impl/TrackImpl.java b/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/tracking/impl/TrackImpl.java
index f45ead7b68d..de350e75ac7 100644
--- a/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/tracking/impl/TrackImpl.java
+++ b/java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/tracking/impl/TrackImpl.java
@@ -313,19 +313,36 @@ public class TrackImpl<FixType extends Timed> implements Track<FixType> {
     }
 
     protected boolean add(FixType fix) {
+        return add(fix, /* replace */ false);
+    }
+
+    protected boolean add(FixType fix, boolean replace) {
         lockForWrite();
         try {
-            return addWithoutLocking(fix);
+            return addWithoutLocking(fix, replace);
         } finally {
             unlockAfterWrite();
         }
     }
 
     /**
-     * The caller must ensure to hold the write lock for this track when calling this methos
+     * The caller must ensure to hold the write lock for this track when calling this method.
+     * 
+     * @param replace
+     *            whether or not to replace an existing fix in the track that is equal to {@link #fix} as defined by the
+     *            comparator used for the {@link #fixes} set. By default this is a comparator only comparing the
+     *            fixes' time stamps. Subclasses may use different comparator implementations.
      */
-    protected boolean addWithoutLocking(FixType fix) {
-        return getInternalRawFixes().add(fix);
+    protected boolean addWithoutLocking(FixType fix, boolean replace) {
+        final boolean result;
+        final boolean added = getInternalRawFixes().add(fix);
+        if (!added && replace) {
+            getInternalRawFixes().remove(fix);
+            result = getInternalFixes().add(fix);
+        } else {
+            result = added;
+        }
+        return result;
     }
 
     @Override
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/base/impl/RegattaImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/base/impl/RegattaImpl.java
index 75982559fa0..6c39ac72caa 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/base/impl/RegattaImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/base/impl/RegattaImpl.java
@@ -792,6 +792,6 @@ public class RegattaImpl extends NamedImpl implements Regatta, RaceColumnListene
     public void deregisterCompetitors(Iterable<Competitor> competitors) {
         RegattaLog regattaLog = getRegattaLike().getRegattaLog();
         CompetitorDeregistrator<RegattaLog, RegattaLogEvent, RegattaLogEventVisitor> deregisterer = new CompetitorDeregistrator<>(regattaLog, competitors, regattaLogEventAuthorForRegatta);
-        deregisterer.analyze();
+        deregisterer.deregister(deregisterer.analyze());
     }
 }
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/leaderboard/impl/AbstractLeaderboardImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/leaderboard/impl/AbstractLeaderboardImpl.java
index 4c3ef7f9c9f..be0e19e182e 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/leaderboard/impl/AbstractLeaderboardImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/leaderboard/impl/AbstractLeaderboardImpl.java
@@ -224,6 +224,6 @@ public abstract class AbstractLeaderboardImpl extends AbstractSimpleLeaderboardI
     public void deregisterCompetitors(Iterable<Competitor> competitors) {
         RegattaLog regattaLog = getRegattaLike().getRegattaLog();
         CompetitorDeregistrator<RegattaLog, RegattaLogEvent, RegattaLogEventVisitor> deregisterer = new CompetitorDeregistrator<>(regattaLog, competitors, regattaLogEventAuthorForAbstractLeaderboard);
-        deregisterer.analyze();
+        deregisterer.deregister(deregisterer.analyze());
     }
 }
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/DynamicTrack.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/DynamicTrack.java
index e1e728cf9c6..970e9fbf522 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/DynamicTrack.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/DynamicTrack.java
@@ -4,7 +4,25 @@ import com.sap.sse.common.Timed;
 
 public interface DynamicTrack<FixType extends Timed> extends Track<FixType> {
     /**
+     * Tries to add {@code fix} to this track. If an {@link #equals(Object) equal} fix already exists
+     * in this track, the track remains unchanged and {@code false} will be returned.
+     * 
      * @return <code>true</code> if the element was added, <code>false</code> otherwise.
      */
     boolean add(FixType fix);
+
+    /**
+     * Tries to add {@code fix} to this track. If an {@link #equals(Object) equal} fix already exists
+     * in this track and {@code replace} is {@code false}, the track remains unchanged and {@code false} will be returned.
+     * If {@code replace} is {@code true}, an equal (by definition of the comparator used for the fixes set) fix will
+     * replace the fix contained in this track.
+     * 
+     * @param replace
+     *            whether or not to replace an existing fix in the track that is equal to {@link #fix} as defined by the
+     *            comparator used for the {@link #fixes} set. By default this is a comparator only comparing the fixes'
+     *            time stamps. Subclasses may use different comparator implementations.
+     * 
+     * @return <code>true</code> if the element was added, <code>false</code> otherwise.
+     */
+    boolean add(FixType fix, boolean replace);
 }
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixMovingTrackImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixMovingTrackImpl.java
index 474da3db2e6..77064a32927 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixMovingTrackImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixMovingTrackImpl.java
@@ -47,7 +47,7 @@ public class DynamicGPSFixMovingTrackImpl<ItemType> extends GPSFixTrackImpl<Item
      */
     @Override
     public void addGPSFix(GPSFixMoving gpsFix) {
-        add(gpsFix);
+        add(gpsFix, /* replace */ true);
     }
     
     @Override
@@ -55,6 +55,11 @@ public class DynamicGPSFixMovingTrackImpl<ItemType> extends GPSFixTrackImpl<Item
         return super.add(new CompactGPSFixMovingImpl(fix));
     }
 
+    @Override
+    public boolean add(GPSFixMoving fix, boolean replace) {
+        return super.add(new CompactGPSFixMovingImpl(fix), replace);
+    }
+
     /**
      * Interpolates linearly between the two fixes based on their time difference and distance. This
      * intentionally ignores the {@link GPSFixMoving#getSpeed() speed values} provided by the fixes
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixTrackImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixTrackImpl.java
index 6f4f07f216e..2627da19daf 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixTrackImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicGPSFixTrackImpl.java
@@ -12,12 +12,17 @@ public class DynamicGPSFixTrackImpl<ItemType> extends GPSFixTrackImpl<ItemType,
     }
 
     public void addGPSFix(GPSFix gpsFix) {
-        add(gpsFix);
+        add(gpsFix, /* replace */ true);
     }
     
     @Override
     public boolean add(GPSFix fix) {
-        return super.add(new CompactGPSFixImpl(fix));
+        return super.add(fix);
+    }
+
+    @Override
+    public boolean add(GPSFix fix, boolean replace) {
+        return super.add(new CompactGPSFixImpl(fix), replace);
     }
 
     @Override
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicTrackImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicTrackImpl.java
index f6f8907c7c2..d91585aa471 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicTrackImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/DynamicTrackImpl.java
@@ -17,4 +17,9 @@ public class DynamicTrackImpl<FixType extends Timed> extends TrackImpl<FixType>
     public boolean add(FixType fix) {
         return super.add(fix);
     }
+
+    @Override
+    public boolean add(FixType fix, boolean replace) {
+        return super.add(fix, replace);
+    }
 }
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/GPSFixTrackImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/GPSFixTrackImpl.java
index 1259e536ac1..208b4059cd4 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/GPSFixTrackImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/GPSFixTrackImpl.java
@@ -1106,7 +1106,7 @@ public class GPSFixTrackImpl<ItemType, FixType extends GPSFix> extends TrackImpl
         lockForWrite();
         try {
             firstFixInTrack = getRawFixes().isEmpty();
-            result = addWithoutLocking(fix);
+            result = addWithoutLocking(fix, /* replace */ false);
             if (!validityCachingSuspended) {
                 invalidateValidityAndEstimatedSpeedAndDistanceCaches(fix);
             }
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/WindTrackImpl.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/WindTrackImpl.java
index 796f25602a5..8ce0c7194ed 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/WindTrackImpl.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/WindTrackImpl.java
@@ -108,9 +108,14 @@ public class WindTrackImpl extends TrackImpl<Wind> implements WindTrack {
     }
 
     @Override
-    public boolean add(Wind wind) {
+    public boolean add(Wind fix) {
+        return super.add(fix);
+    }
+
+    @Override
+    public boolean add(Wind wind, boolean replace) {
         final CompactWindImpl compactWind = new CompactWindImpl(wind);
-        final boolean result = super.add(compactWind);
+        final boolean result = super.add(compactWind, replace);
         notifyListenersAboutReceive(compactWind);
         return result;
     }
diff --git a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.java b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.java
index 45104e186c4..69e1aad771f 100644
--- a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.java
+++ b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.java
@@ -139,7 +139,6 @@ public interface TextMessages extends Messages {
     String latestRaceResultsHeadline();
     String latestRaceResultsIsNew();
     String latestRaceResultsIsUpdated();
-    String latestRaceResultsRaceCountLabel();
     String latestRaceResultsRaceCountUnit();
     String latestRaceResultsRefresh();
     String leaderboardQuickAccessLabel();
diff --git a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.properties b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.properties
index 7365690323b..68759ed7726 100644
--- a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.properties
+++ b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages.properties
@@ -128,7 +128,6 @@ headerSponsoring=Sponsoring
 latestRaceResultsHeadline=Latest Official Race Results
 latestRaceResultsIsNew=New
 latestRaceResultsIsUpdated=Updated
-latestRaceResultsRaceCountLabel=Result after
 latestRaceResultsRaceCountUnit=races
 latestRaceResultsRefresh=refresh
 leaderboardQuickAccessLabel=Leaderboard Quick Access
diff --git a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_de.properties b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_de.properties
index 66836911be6..9076a2dfd83 100644
--- a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_de.properties
+++ b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_de.properties
@@ -128,7 +128,6 @@ headerSponsoring=Sponsoren
 latestRaceResultsHeadline=Letzten ofiziellen Ergebnisse
 latestRaceResultsIsNew=Neu
 latestRaceResultsIsUpdated=Aktualisiert
-latestRaceResultsRaceCountLabel=Ergebnis nach
 latestRaceResultsRaceCountUnit=Rennen
 latestRaceResultsRefresh=aktualisieren
 leaderboardQuickAccessLabel=Ergebnisliste Schnellzugang
diff --git a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_ru.properties b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_ru.properties
index 672db2ce8f1..46a2645ad4b 100644
--- a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_ru.properties
+++ b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_ru.properties
@@ -128,7 +128,6 @@ headerSponsoring=Sponsoring
 latestRaceResultsHeadline=Latest Official Race Results
 latestRaceResultsIsNew=New
 latestRaceResultsIsUpdated=Updated
-latestRaceResultsRaceCountLabel=Result after
 latestRaceResultsRaceCountUnit=races
 latestRaceResultsRefresh=refresh
 leaderboardQuickAccessLabel=Leaderboard Quick Access
diff --git a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_zh.properties b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_zh.properties
index 09b2d649884..28c706f9abe 100644
--- a/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_zh.properties
+++ b/java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/common/client/i18n/TextMessages_zh.properties
@@ -159,7 +159,6 @@ headerSponsoring=Sponsoring
 latestRaceResultsHeadline=Latest Official Race Results
 latestRaceResultsIsNew=New
 latestRaceResultsIsUpdated=Updated
-latestRaceResultsRaceCountLabel=Result after
 latestRaceResultsRaceCountUnit=races
 latestRaceResultsRefresh=refresh
 leaderboardQuickAccessLabel=Leaderboard Quick Access