Coastal Services Center

---

Determining Navigability (1 of 5)

---

Is the Water Body Navigable?

Navigability varies depending on

• The type of water body
• The legal definition of “navigable waters”

Determining Navigability by Tidal Influence

States define all waters that are subject to the ebb and flow of the tide as navigable in law and therefore subject to the Public Trust. Determining tidal influence, however, is not a simple matter.

• Tidal influence may reach far inland with a minimal flux, and the rhythm of the high and low tide may be hours behind that on the coast. Tidal influence may be difficult to determine when the waters in question are far from the ocean.
• The lack of salinity is also not conclusive. Waters may be totally fresh but still ebb and flow in response to the oceanic tides.