title: HNLMS Zeeleeuw (1987)
text: # HNLMS Zeeleeuw (1987)
  
  HNLMS Zeeleeuw (S803) is a Walrus-class submarine of the Royal Netherlands Navy. She entered service in 1990 as the first submarine of the Walrus class, after the intended lead ship, HNLMS Walrus, was delayed for a long period following a serious fire during construction. Zeeleeuw has been deployed both for naval exercises and in combat operations around the world. Furthermore, the submarine plays an important role by performing intelligence operations. The submarine has undergone a mid-life maintenance and upgrade program between 2014 and 2016, and is currently in active service.
  
  ## Activities
  
  * In 2010 HNLMS Zeeleeuw took part in Operation Ocean Shield.
  
  ## Maintenance and upgrade
  
  In 2014 HNLMS Zeeleeuw was taken out of service after years of service by the Royal Netherlands Navy to perform maintenance and modernize its systems. During the upgrade program, the submarine was upgraded with modern systems. The ageing GIPSY combat system was replaced with the more modern Guardion combat system. Besides changing the software suite, hardware components were either replaced or upgraded with newer versions. The Medium Range Sonar (MRS) and Long Range Sonar (LRS) were replaced. A new sonar was added, the Mine and Obstacle Avoidance Sonar (MOAS). The consoles and screens in the command room were upgraded to more modern versions, while the navigation and attack periscopes went from being depended on analog sensors to digital sensors. This was done by replacing several masts. Lastly, the Mark 48 torpedoes were upgraded from mod 4 to the more recent mod 7.
  
  