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 b8533d97b5c..226cb5ac576 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
@@ -32,12 +32,18 @@ public class DynamicTrackImpl<ItemType, FixType extends GPSFix> extends
         }
         if (logger.isLoggable(Level.FINEST)) {
             FixType last;
-            logger.finest("GPS fix "+gpsFix+" for "+getTrackedItem()+", isValid="+gpsFix.isValid()+", time/distance/speed from last: "+
+            lockForRead();
+            try {
+                logger.finest("GPS fix "+gpsFix+" for "+getTrackedItem()+", isValid="+isValid(getInternalRawFixes(), gpsFix)+
+                    ", time/distance/speed from last: "+
                     ((last=getInternalRawFixes().lower(gpsFix))==null
                     ? "null"
-                    : (gpsFix.getTimePoint().asMillis()-last.getTimePoint().asMillis())+"ms/"+
+                    : (gpsFix.getTimePoint().asMillis()-last.getTimePoint().asMillis()+"ms/"+
                       gpsFix.getPosition().getDistance(last.getPosition())) + "/"+
-                      gpsFix.getPosition().getDistance(last.getPosition()).inTime(gpsFix.getTimePoint().asMillis()-last.getTimePoint().asMillis()));
+                      gpsFix.getPosition().getDistance(last.getPosition()).inTime(gpsFix.getTimePoint().asMillis()-last.getTimePoint().asMillis())));
+            } finally {
+                unlockAfterRead();
+            }
         }
         for (GPSTrackListener<ItemType, FixType> listener : getListeners()) {
             listener.gpsFixReceived(gpsFix, getTrackedItem());
diff --git a/java/target/configuration/logging_debug.properties b/java/target/configuration/logging_debug.properties
index b259d27c039..54dd7eb530c 100644
--- a/java/target/configuration/logging_debug.properties
+++ b/java/target/configuration/logging_debug.properties
@@ -19,3 +19,6 @@ java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter
 com.sap.sailing.level = FINEST
 org.eclipse.jetty.level = INFO
 org.apache.activemq.level = INFO
+
+# TTCM logging is disabled by default; enable by commenting out the following line
+com.sap.sailing.domain.tracking.impl.DynamicTrackImpl.level = OFF