The navigable areas of oceans, rivers, bays, and tidal zones are owned by the public and generally available for public use. A common area of dispute is whether a private property owner has the right to control use of and access to lakes, streams, and rivers on private property (sometimes known as riparian rights)—and whether federal or state governments have the right to regulate use of such waterways.

Much of the question turns on whether the waterway is navigable or unnavigable (nonnavigable). Navigable waters are, as the name implies, waters that can be navigated—or easily made navigable—traditionally for purposes of transporting goods in intrastate (within one state) or interstate (between two or more states) commerce.

Thus, a waterway in its original condition might have had substantial obstructions (falls, rapids, sand bars, bridges, portages, shifting currents, or similar obstructions) that were overcome by frontier boats or portages and used as a channel of commerce—even though boats had to be removed from the water in some stretches, or logs be brought around an obstruction by means of artificial chutes. But the question is ultimately a matter of degree and there is some point beyond which navigability cannot be established.

Lakes and rivers are generally navigable waters, and smaller bodies of water such as streams may also be navigable. The U.S. Supreme Court has created four tests for determining what constitutes navigable waters under federal law: (1) whether the body of water is subject to the ebb and flow of the tide; (2) whether the body of water connects with a continuous interstate waterway; (3) whether the body of water has navigable capacity; and (4) whether the body of water is actually navigable.

Navigable waterways (as defined by federal law) are under the jurisdiction of the federal government—rather than states or municipalities—based on the Commerce Clause (Article I, Section 8) of the U.S. Constitution. But waterways that do not meet the definition of navigable waters under federal law are under the jurisdiction of states and municipalities and may be considered navigable waters under state and municipal laws. Waterways that are unnavigable under both federal and state law may be subject to the control of the streamside landowner.

Laws vary from state to state, but some state courts have ruled that where the state legislature refuses to create a public trust for recreational purposes in unnavigable streams, the courts should not alter the legislature's statement of public policy by judicial legislation. These courts have reasoned that if unnavigable waters are to be appropriated for recreational use, the legislative process is the proper method to achieve this goal.

And in some states the public trust doctrine—a legal theory that requires states to hold and preserve certain natural resources for the public’s use and enjoyment—requires that navigable waterways be available for public use (at least flotation) even though they are located on private land.

In Hawaii, the public generally owns and has the right to use navigable areas of oceans, rivers, bays, and tidal zones. The determination of whether a waterway is navigable or not is crucial in establishing who has control over it. Navigable waters are those that can be used for transportation in commerce and are under federal jurisdiction based on the Commerce Clause of the U.S. Constitution. The U.S. Supreme Court has established four tests to determine navigability under federal law, which include the ebb and flow of the tide, connection with a continuous interstate waterway, navigable capacity, and actual navigability. Waterways that are not considered navigable under federal law fall under state jurisdiction. In Hawaii, as in other states, the public trust doctrine may apply, which holds that navigable waterways should be preserved for public use and enjoyment, even if they cross private property. However, for waterways that are deemed unnavigable under both federal and state law, control may rest with the adjacent landowner. The legislative process is typically the appropriate method for designating unnavigable waters for public recreational use if the state legislature chooses to do so.