Introduction – World Hydrography Day is celebrated on June 21 annually to honor the work and the importance of hydrographers. This day aims is to increase awareness about the protection of safe navigation and also concentrate on spreading the work of hydrographers. International Hydrographic Organization (IHO) is also celebrating the 100^th anniversary of its formation this year.

Hydrography is a branch of applied sciences, which mainly deals with the description and measurement of the physical features of coastal areas, seas, lakes, rivers, and oceans. The work of hydrographers is to predict changes in the water body for the safety of navigation and support other marine activities.

History – The International Hydrographic Bureau came into existence in the year 1921. The purpose of the International Hydrographic Bureau is to provide a safe mechanism for talk between governments on matters associated with safe navigation, protection, and technical standards. The name was adopted as an International Hydrographic Organization (IHO) was formed in the year 1970.

When International Hydrographic Organization came into existence, the idea to celebrate World Hydrographic Day to honor the work of hydrographers in the year 2005. The United Nations General Assembly welcomed this idea in resolution and June 21 was chosen to celebrate the anniversary of the International Hydrographic Organization (IHO).

Significance – The idea to celebrate World Hydrographic Day is to encourage the importance of hydrography with the publish the work of hydrographers. The theme of this day was ‘’Hydrography enabling autonomous technologies’’ in the year 2020 that aimed to highlight the important role of hydrography in autonomous technologies.

How to celebrate this day – On this day, there are several activities such as demonstrations, public events, conferences, dinners, workshops, awards, and distribution of promotional materials are conducted.