Simply put, hydrography is the science of measuring and describing the physical features of oceans, seas, and coastal areas. As such, hydrography plays a critical role in the creation of navigational charts for recreational and commercial boaters.
But the science of hydrography assists us in other ways, too. Hydrography helps scientists identify trends and monitor the long-term changes in the ocean caused by weather, climate, and human impacts. The information that hydrographic surveys provide is also used to help predict the risk of coastal-flooding and contributes to our understanding of natural events like tsunamis and earthquakes.
In celebration of World Hydrography Day on June 21, NOAA created a handy infographic that describes the history, function, and importance of hydrography. The infographic also provides some interesting facts about our waterways, including the following statistics:
- 2,000-3,000 square nautical miles of U.S. waters are surveyed annually
- 43,000 square nautical miles of U.S. waters are considered critical to navigation
- >1000 nautical charts cover 95,000 miles of shoreline and 3.4 million square nautical miles of U.S. waters.