Legal Definitions - ebb and flow

The term "ebb and flow" literally describes the rhythmic rise and fall of ocean tides. In a historical legal context, this phrase was once used to define the boundaries of admiralty jurisdiction in the United States. Admiralty jurisdiction refers to the authority of federal courts to hear cases involving maritime activities, such as shipping, commerce on water, and accidents at sea. Historically, federal courts only had jurisdiction over maritime cases in waters directly affected by the "ebb and flow" of the tides, meaning coastal areas and tidal rivers.

This strict "tidewater limitation" was a significant factor in determining which courts could hear cases involving ships, cargo, and maritime disputes. However, this tidal boundary for admiralty jurisdiction was abandoned by the U.S. Supreme Court in 1851. Since then, federal maritime jurisdiction has expanded to cover all navigable waters, regardless of whether they are influenced by ocean tides.

• Example 1: A Ship Collision in a Tidal Estuary

  Imagine two commercial vessels colliding in a wide river estuary near the coast in 1840. Because this area experiences the regular rise and fall of the tide, a federal admiralty court at that time would have had jurisdiction over any resulting lawsuit, as the incident occurred within the "ebb and flow" of tidal waters. Today, the tidal influence would not be the determining factor; navigability of the waterway would be sufficient for federal jurisdiction.

• Example 2: A Cargo Dispute on the Mississippi River

  Consider a dispute over damaged cargo being transported by steamboat on the upper Mississippi River in 1845, far from any ocean influence. At that time, a federal admiralty court would have lacked jurisdiction over this case because the river at that point did not experience the "ebb and flow" of ocean tides. The parties would have had to pursue their claim in a state court. After 1851, such a case would fall under federal admiralty jurisdiction because the Mississippi River is a navigable waterway.

• Example 3: A Seaman's Injury on the Great Lakes

  Suppose a seaman was injured on a vessel operating on Lake Superior in 1848 and sought to sue for damages. Under the "ebb and flow" limitation, a federal admiralty court would not have had jurisdiction because the Great Lakes, while vast and navigable, are not affected by ocean tides. The seaman would have had to file their lawsuit in a state court. Today, an injury on a vessel on Lake Superior would clearly fall under federal admiralty jurisdiction due to the lake's navigability, irrespective of tidal movement.