diff --git a/Modules/IGT/DataManagement/mitkNavigationDataSet.cpp b/Modules/IGT/DataManagement/mitkNavigationDataSet.cpp
index ea695108e4..ba6660acd4 100644
--- a/Modules/IGT/DataManagement/mitkNavigationDataSet.cpp
+++ b/Modules/IGT/DataManagement/mitkNavigationDataSet.cpp
@@ -1,161 +1,157 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include "mitkNavigationDataSet.h"
 
 mitk::NavigationDataSet::NavigationDataSet( unsigned int numberOfTools )
   : m_NavigationDataVectors(std::vector<std::vector<mitk::NavigationData::Pointer> >()), m_NumberOfTools(numberOfTools)
 {
 }
 
 mitk::NavigationDataSet::~NavigationDataSet( )
 {
 }
 
 bool mitk::NavigationDataSet::AddNavigationDatas( std::vector<mitk::NavigationData::Pointer> navigationDatas )
 {
   // test if tool with given index exist
   if ( navigationDatas.size() != m_NumberOfTools )
   {
     MITK_WARN("NavigationDataSet") << "Tried to add to many or too few navigation Datas to NavigationDataSet. " << m_NavigationDataVectors.size() << " required, tried to add " << navigationDatas.size() << ".";
     return false;
   }
 
   // test for consistent timestamp
   if ( m_NavigationDataVectors.size() > 0)
   {
     for (int i = 0; i < navigationDatas.size(); i++)
       if (navigationDatas[i]->GetIGTTimeStamp() <= m_NavigationDataVectors.back()[i]->GetIGTTimeStamp())
       {
         MITK_WARN("NavigationDataSet") << "IGTTimeStamp of new NavigationData should be newer then timestamp of last NavigationData.";
         return false;
       }
   }
 
   m_NavigationDataVectors.push_back(navigationDatas);
   return true;
 }
 
 mitk::NavigationData::Pointer mitk::NavigationDataSet::GetNavigationDataForIndex( unsigned int index, unsigned int toolIndex ) const
 {
   if ( index >= m_NavigationDataVectors.size() )
   {
     MITK_WARN("NavigationDataSet") << "There is no NavigationData available at index " << index << ".";
     return NULL;
   }
 
   if ( toolIndex >= m_NavigationDataVectors.at(index).size() )
   {
     MITK_WARN("NavigationDataSet") << "There is NavigatitionData available at index " << index << " for tool " << toolIndex << ".";
     return NULL;
   }
 
   return m_NavigationDataVectors.at(toolIndex).at(index);
 }
 
 // Method not yet supported, code below compiles but delivers wrong results
 //mitk::NavigationData::Pointer mitk::NavigationDataSet::GetNavigationDataBeforeTimestamp(
 //  mitk::NavigationData::TimeStampType timestamp, unsigned int toolIndex) const
 //{
 //  if ( toolIndex >= m_NavigationDataVectors.size() )
 //  {
 //    MITK_WARN("NavigationDataSet") << "There is no tool with index " << toolIndex << ".";
 //    return NULL;
 //  }
 //
 //  std::vector<mitk::NavigationData::Pointer>::const_iterator it;
 //
 //  // iterate through all NavigationData objects of the given tool index
 //  // till the timestamp of the NavigationData is greater then the given timestamp
 //  for (it = m_NavigationDataVectors.at(toolIndex).begin();
 //    it != m_NavigationDataVectors.at(toolIndex).end(); ++it)
 //  {
 //    if ( (*it)->GetIGTTimeStamp() > timestamp) { break; }
 //  }
 //
 //  // first element was greater than timestamp -> return null
 //  if ( it == m_NavigationDataVectors.at(toolIndex).begin() )
 //  {
 //    MITK_WARN("NavigationDataSet") << "No NavigationData was recorded before given timestamp.";
 //    return NULL;
 //  }
 //
 //  // return last element smaller than the given timestamp
 //  return *(it-1);
 //}
 
 unsigned int mitk::NavigationDataSet::GetNumberOfTools()
 {
   return m_NavigationDataVectors.size();
 }
 
 unsigned int mitk::NavigationDataSet::GetNumberOfNavigationDatas(bool check)
 {
   if (this->GetNumberOfTools() == 0) { return 0; };
 
   unsigned int number = m_NavigationDataVectors.at(0).size();;
 
   if (check)
   {
     for (std::vector<std::vector<NavigationData::Pointer> >::iterator it = m_NavigationDataVectors.begin()+1;
       it != m_NavigationDataVectors.end(); ++it)
     {
       if (it->size() != number)
       {
         MITK_WARN << "Number of NavigationData objects differs for different tools.";
         return -1;
       }
     }
   }
 
   return number;
 }
 
 // ---> methods necessary for BaseData
 void mitk::NavigationDataSet::SetRequestedRegionToLargestPossibleRegion()
 {
 }
 
 bool mitk::NavigationDataSet::RequestedRegionIsOutsideOfTheBufferedRegion()
 {
   return false;
 }
 
 bool mitk::NavigationDataSet::VerifyRequestedRegion()
 {
   return true;
 }
 
 void mitk::NavigationDataSet::SetRequestedRegion(const DataObject * )
 {
 }
 // <--- methods necessary for BaseData
 
 // ---> methods for Iterators
 
 mitk::NavigationDataSet::NavigationDataSetIterator mitk::NavigationDataSet::Begin()
 {
-  //TODO default implementation
-  mitk::NavigationDataSet::NavigationDataSetIterator result;
-  return result;
+  return m_NavigationDataVectors.begin();
 }
 
 mitk::NavigationDataSet::NavigationDataSetIterator mitk::NavigationDataSet::End()
 {
-  //TODO default implementation
-  mitk::NavigationDataSet::NavigationDataSetIterator result;
-  return result;
+  return m_NavigationDataVectors.end();
 }