Navigation Rules

Chris Riley by Chris Riley Updated on January 3, 2021. In nauticalknowhow

Navigation Rules

Navigation RulesThe “Rules of the Road” or Collision Avoidance Regulations (COLREGS) 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. They are many in number and cover almost every imaginable sequence of events which may lead to collision. You do not have to memorize them all but be aware of the basic rules which apply in order to operate safely on the water. You will be using terms when dealing with the rules of the road which 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.

  • Vessel – Every craft of any description used or capable of being used on the water.
  • Power Driven Vessel (Motorboat) – 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.)
  • Underway – Not at anchor, aground or attached to the dock or shore.
  • Danger Zone – An arc of 112.5 degrees measured from dead ahead to just aft of the starboard beam.
  • Right-of-way – The right and duty to maintain course and speed.
  • Stand-On Vessel – The vessel which has the right-of-way.
  • Give-Way Vessel – The vessel which must keep clear of the stand-on vessel.
  • Visible (when applied to lights) – Visible on a dark, clear night.
  • Short Blast – A blast of one to two seconds duration.
  • Prolonged Blast – A blast of four to six seconds duration.

Good Seamanship

Practicing the art of good seamanship is a talent that is developed over time by acquiring knowledge and skills. You must keep safety foremost in your mind when operating your boat. Do what you can to stay out of the way of other boats and always proceed at a safe speed. Safe speed means taking into consideration the current operating conditions and your own level of skill and experience.

Most specific speed regulations are local ordinances or state laws. Many states have speed and distance regulations that determine how close you can operate to other vessels, the shoreline or docking area, and swimming areas. For example, some state regulations require that you maintain a no-wake speed when within 250 feet of shore or when within 100 feet of another vessel. Be sure to check with state and local authorities to determine what regulations apply to you.

Proper Lookout

The rules are very specific about maintaining a proper lookout. We must keep eyes and ears open to observe or hear something which may endanger someone or affect their safety. You must look up for bridge clearances and power lines, down for floats, swimmers, logs and divers flags and side to side for traffic prior to turning your boat. A proper lookout can avoid surprises.

A good rule to follow is to assign one or more people to have no other assigned responsibilities except the task of lookout. They can then rotate the lookout duty.

Sound Signals

Vessels are required to sound signals any time that they are in close quarters and risk of collision exists. The following signals are the only ones to be used to signal a vessel’s intentions (inland rules only).

  • One short blast – I intend to change course to starboard.
  • Two short blasts – I intend to change course to port.
  • Three short blasts – I am operating astern propulsion (backing up).
  • Five or more short and rapid blasts – Danger or doubt signal (I don’t understand your intent).

Note: Inland rules use sound signals to indicate intent to maneuver. In international rules the signals are given when the maneuver is being executed.

Vessels indicate their intention to maneuver by using sound signals. If you do not agree with or understand clearly what the other vessel’s intentions are you should sound the danger or doubt signal (5 short, rapid blasts). Each vessel should then slow or stop until signals for safe passing are sounded, understood and agreed to.

The danger or doubt signal can also be used to tell another vessel that its action is dangerous. If a boat is backing up into an obstruction you would sound the danger signal to warn the operator.


There are two sets of navigation rules; inland and international. A nautical chart will show you the demarcation lines where the rules change from international to inland and vice versa. In general, these demarcation lines follow the coastline and cross inlets and bays. On the seaward side of the demarcation lines international rules apply. We will concentrate on the inland rules, since most of your recreational boating will occur on the landward side of the demarcation lines.

The Nav Rules are written with the understanding that not all boats can maneuver with the same ease. Therefore, Rule 18 states that certain vessels have the right-of-way over other vessels by virtue of their ability to maneuver.

A power driven vessel underway must keep out of the way of the following:

    • A sailing vessel, under sail only, and vessels propelled by oars or paddles. (Note: when a sailboat has its motor running, it is considered a power driven vessel).
    • A vessel engaged in fishing, whose fishing equipment restricts its maneuverability. This does not include a sport fisher or party boat and generally means a commercial fishing vessel.
    • A vessel with restricted maneuverability such as a dredge or tow boat, a boat engaged in work that restricts it to a certain area, or a vessel transferring supplies to another vessel.
    • A vessel not under command – broken down.

Each of these vessels must keep out of the way of the next vessel in the hierarchy. For example, a sailboat must keep out of the way of a vessel engaged in fishing, which in turn must keep out of the way of a vessel with restricted maneuverability. And everyone must keep out of the way of a vessel not under command.

When two power driven vessels are in sight of one another and the possibility of collision exists, one vessel is designated by the rules as the stand-on vessel and the other is designated as the give-way vessel. The stand-on vessel, the boat with the right of way, should maintain its course and speed. The give-way vessel must take early and substantial action to avoid collision. If it becomes apparent that the actions taken (or not taken) by the give-way vessel are dangerous or insufficient, the stand-on vessel must act to avoid collision.




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