Water science news, explainers, and statistics covering freshwater, hydrology, lakes, rivers, groundwater, ice, and Earth’s connected water systems.
Modern ships can determine their position with satellites and display it on electronic charts. They carry radar and depth sounders, supported by radios that earlier mariners could not imagine. Yet working lighthouses still mark harbor entrances and isolated hazards at headlands around the world. Their role has changed from being a vessel’s principal guide to…
More
The Great Loop is a boating route that circles much of eastern North America through connected rivers, canals, lakes and protected coastal waterways. Its course is flexible, but a typical circuit passes through the Atlantic Intracoastal Waterway, the Great Lakes, the inland river system and the Gulf Coast before returning to its starting point. NOAA…
A fish ladder is a water-filled route that helps migrating fish move around a dam or another barrier. Instead of making one impossible leap, a fish enters flowing water at the base. It advances through smaller changes in elevation while resting in pools between them. NOAA’s definition of a fish ladder, also called a fishway,…
The Chesapeake Bay is the largest estuary in the United States. It stretches roughly 200 miles from the Susquehanna River at Havre de Grace, Maryland, to the Atlantic Ocean between Cape Charles and Cape Henry in Virginia. Across that distance, river water gradually mixes with salt water pushed inland by tides. NOAA’s profile of the…
