Navigation Rules - International and Inland Rules

Navigation Rules for boats

The "Navigation Rules" or Collision Avoidance Regulations were designed to give direction to vessels in order to set a standard that everyone could follow in order to prevent collisions of two or more vessels.  

The rules are laid out to describe International Rules and Inland Rules. Although many are the same for both International and Inland, there are some differences that should be noted. 

You will be using terms when dealing with the rules of the road that may be unfamiliar to you. Because the rules are federal laws, the definitions of these terms are important. The following terms are found throughout the rules of the road. You should have a thorough understanding of their meaning.

The following rule about responsibility is somewhat confusing if you are not a student of the rules. Just read them and the meaning will be explained after each one. This rule applies to both International and Inland rules.

Nothing in these rules shall exonerate any vessel, or the owner, master, or crew thereof, from the consequences of any neglect to comply with these rules or of the neglect of any precaution which may be required by the ordinary practice of seamen, or by the special circumstances of the case.

Means: If something happens, such as a collision, everyone is at fault.

- In construing and complying with these rules due regard shall be had to all dangers of navigation and collision and to any special circumstances, including the limitations of the vessels involved, which may make a departure from these rules necessary to avoid immediate danger.

Means: If you are in danger of collision, both boats are obligated to do everything possible to prevent the collision even if doing so deviates from the rules. 

Do whatever is necessary to avoid the collision!

The following definitions apply to both International and Inland Rules:

  • Vessel - Every craft of any description used or capable of being used on the water.

  • Power Driven Vessel  - Any vessel propelled by machinery.

  • Sailing Vessel - Any vessel under sail alone with no mechanical means of propulsion. (A sailboat propelled by machinery is a motorboat.)

  • Vessel engaged in fishing means any vessel fishing with nets, lines, trawls or other fishing apparatus that restricts maneuverability, but does not include a vessel fishing with trolling lines or other fishing apparatus which do not restrict maneuverability.

  • Seaplane includes any aircraft designed to maneuver on the water.

  • Underway- Not at anchor, aground or attached to a dock or the shore.

  • Vessels are in sight of one another only when one can be observed visually from the other.

  • Restricted visibility means any condition in which visibility is restricted by fog, mist, falling snow, heavy rainstorms, sand storms or any other similar causes.

The following two definitions apply to Inland Rules only:

  • Western Rivers means the Mississippi River, its tributaries, South Pass, and Southwest Pass, to the navigational demarcation lines dividing the high seas from harbors, rivers, and other inland waters of the United States, and the Port Allen-Morgan City Alternate Route, and that part of the Atchafalaya River above its junction with the Port Allen-Morgan City Alternate Route including the Old River and the Red River.

  • Great Lakes means the Great Lakes and their connecting and tributary waters, including the Calumet River as far as the Thomas J. O'Brien Lock and Controlling Works (between mile 326 and 327), the Chicago River as far as the east side of the Ashland Avenue Bridge (between mile 321 and 322), and the Saint Lawrence River as far east as the lower exit of Saint Lambert Lock.