diff --git a/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/CompetitorDTOImpl.java b/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/CompetitorDTOImpl.java
index b8fb1f8cc63..f6ee74ec6cd 100755
--- a/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/CompetitorDTOImpl.java
+++ b/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/CompetitorDTOImpl.java
@@ -2,6 +2,15 @@ package com.sap.sailing.domain.common.dto;
 
 import java.io.Serializable;
 
+/**
+ * Equality and hash code are based on the {@link #getIdAsString() ID}, the {@link #getSailID() sail number}, the
+ * {@link #getBoatClass() boat class} (whose equality and hash code, in turn, depends on its name) and the
+ * {@link #getThreeLetterIocCountryCode() IOC country code}. Note that the three latter properties are subject
+ * to change for a competitor while the ID remains unchanged.
+ * 
+ * @author Axel Uhl (d043530)
+ * 
+ */
 public class CompetitorDTOImpl extends NamedDTO implements CompetitorDTO, Serializable {
     private static final long serialVersionUID = -4997852354821083154L;
     private String twoLetterIsoCountryCode;
@@ -27,8 +36,11 @@ public class CompetitorDTOImpl extends NamedDTO implements CompetitorDTO, Serial
     @Override
     public int hashCode() {
         final int prime = 31;
-        int result = 1;
-        result = prime * getIdAsString().hashCode();
+        int result = super.hashCode();
+        result = prime * result + ((boatClass == null) ? 0 : boatClass.hashCode());
+        result = prime * result + ((idAsString == null) ? 0 : idAsString.hashCode());
+        result = prime * result + ((sailID == null) ? 0 : sailID.hashCode());
+        result = prime * result + ((threeLetterIocCountryCode == null) ? 0 : threeLetterIocCountryCode.hashCode());
         return result;
     }
 
@@ -36,15 +48,30 @@ public class CompetitorDTOImpl extends NamedDTO implements CompetitorDTO, Serial
     public boolean equals(Object obj) {
         if (this == obj)
             return true;
-        if (obj == null)
+        if (!super.equals(obj))
             return false;
         if (getClass() != obj.getClass())
             return false;
         CompetitorDTOImpl other = (CompetitorDTOImpl) obj;
-        if (getIdAsString() == null) {
-            if (other.getIdAsString() != null)
+        if (boatClass == null) {
+            if (other.boatClass != null)
                 return false;
-        } else if (!getIdAsString().equals(other.getIdAsString()))
+        } else if (!boatClass.equals(other.boatClass))
+            return false;
+        if (idAsString == null) {
+            if (other.idAsString != null)
+                return false;
+        } else if (!idAsString.equals(other.idAsString))
+            return false;
+        if (sailID == null) {
+            if (other.sailID != null)
+                return false;
+        } else if (!sailID.equals(other.sailID))
+            return false;
+        if (threeLetterIocCountryCode == null) {
+            if (other.threeLetterIocCountryCode != null)
+                return false;
+        } else if (!threeLetterIocCountryCode.equals(other.threeLetterIocCountryCode))
             return false;
         return true;
     }
diff --git a/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/PreviousCompetitorDTOImpl.java b/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/PreviousCompetitorDTOImpl.java
index f91b990cd9e..3ce385a3fd7 100755
--- a/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/PreviousCompetitorDTOImpl.java
+++ b/java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/dto/PreviousCompetitorDTOImpl.java
@@ -1,5 +1,11 @@
 package com.sap.sailing.domain.common.dto;
 
+/**
+ * Equality and hash code are based on the index pointing into a previous leaderboard's competitors list.
+ * 
+ * @author Axel Uhl (d043530)
+ * 
+ */
 public class PreviousCompetitorDTOImpl implements CompetitorDTO {
     private static final long serialVersionUID = 8820028699103040805L;
     private int indexInPreviousCompetitorList;
@@ -14,6 +20,28 @@ public class PreviousCompetitorDTOImpl implements CompetitorDTO {
     protected int getIndexInPreviousCompetitorList() {
         return indexInPreviousCompetitorList;
     }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + indexInPreviousCompetitorList;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        PreviousCompetitorDTOImpl other = (PreviousCompetitorDTOImpl) obj;
+        if (indexInPreviousCompetitorList != other.indexInPreviousCompetitorList)
+            return false;
+        return true;
+    }
     
     @Override
     public String getTwoLetterIsoCountryCode() {