World Hydrography Day This day is observed on 21 June every year to increase public awareness about hydrography science. Every year the International Hydrographic Organisation (IHO) and its international members celebrate this day. This is related to science and technology which will get information about oceans ,sea creature life ,temperature ,atmosphere bio ,measurements and predictions and a lot .It always stand-up for to save lives and researching deals with many aspects of safe navigation .