A more thorough explanation:

Definition: Navigable water refers to a body of water that can be used for transportation and commerce. It can be affected by the ebb and flow of the tide or can be an inland river that is capable of supporting commerce.

For example, the Mississippi River is a navigable waterway that is used for transportation and commerce. It is an inland river that is capable of supporting large ships and barges that transport goods and products.

The term "navigable water" is important because it affects many legal issues, such as admiralty jurisdiction, regulatory authority, and ownership disputes. Congress has broad jurisdiction over all navigable waters of the United States under the Commerce Clause.