ANS:A - June 21

World Hydrography Day is celebrated globally on June 21st each year. Established by the International Hydrographic Organization (IHO) in 2005, this day aims to raise awareness about the importance of hydrography—the science of measuring and describing the physical features of bodies of water and the surrounding land. The observance underscores the critical role that hydrographic data plays in ensuring safe navigation, supporting environmental protection, and promoting sustainable development in marine and freshwater environments. On World Hydrography Day, various events and activities are organized to highlight advancements in hydrographic technology, the value of accurate and up-to-date nautical charts, and the contributions of hydrographers to maritime safety and environmental conservation. The day also serves as a platform to acknowledge the work of hydrographic organizations, promote collaboration among international stakeholders, and encourage the continued development of hydrographic capabilities to address emerging challenges in oceanography and navigation. Celebrating World Hydrography Day reflects a global commitment to advancing maritime safety, environmental stewardship, and the effective management of aquatic resources.