HS Stravon A-476, Hydrographic / Oceanographic vessel of the Hellenic Navy.
The Hellenic Navy Hydrographic Service (HNHS), is an independent service of the Greek Navy General Staff, is responsible for hydrographic surveying and production and sale of charts. The first naval hydrographic office was created in 1905 and its first mission was the hydrographic survey of Maliakos Gulf. Its first nautical chart was issued in 1909 and in 1919 the Hellenic Navy became a founding member of the International Hydrographic Organization (IHO). The hydrographic office evolved into the independent naval Hydrographic Service in 1921.