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Rules of the Road

Whenever you meet another boat, it’s like approaching an unmarked intersection in your car. Knowing a few, simple right of way rules will help you avoid a collision. Just as motorists must know what to do when approaching a four way stop, every crossing situation at sea is like approaching an unmarked intersection. The good news is that there are rules to govern the action of each vessel. The bad news is that many vessel operators do not know the rules.
The Rules state that every vessel shall use all available means appropriate to the prevailing conditions to determine if a risk of collision exists. If there is any doubt, such risk shall be deemed to existFurther, every vessel must proceed at a safe speed at all times. Several factors should be considered when determining safe speed, including but not limited to the state of visibility, traffic density, your vessel's maneuverability, with special reference to stopping distance and turning ability. At night, consider the presence of background lights such as those from shore, or from the back-scatter of your vessel's own lights. Consider also the state of wind, sea, and current, and the proximity of navigational hazards.
The Rules specifically require that any action taken to avoid collision, if the circumstances allow, will be positive, made in ample time, and in keeping with good seamanship. Any changes in course or speed should be large enough to be readily apparent to the other vessel visually or by radar; avoid a small series of changes.
Every time you meet another boat, one of you will become the stand-on vessel and the other becomes the give-way vessel. The stand-on has the right-of-way and maintains course and speed. The give-way vessel is required to alter course and speed. Both of these actions are designed to avoid a collision.
The Rules of the Road are published by the U. S. Government Printing Office, and are available in any boating supply store. Every boat owner should have a copy, but they are mandatory to be kept on vessels over 10 meters (39 feet) in length.
The Rules are divided into a few major sections:
(1) General
(2) Steering and Sailing Rules
(3) Lights and Shapes
(4) Sound and Light Signals
Do I Have a Potential Collision Situation?
When the distance between two vessels decreases and the relative angle of the other vessel off the bow remains the same, then you will soon be trying to occupy the same spot in the water - a collision situation.
The main situations of collision risk are overtaking, meeting head-on, and crossing. When one of two vessels is to keep out of the way (give-way vessel), the other, the stand-on vessel, must maintain course and speed. The stand-on vessel must take avoiding action when it becomes apparent that the vessel required to give way is not taking appropriate action.
The Crossing Rule
Both International and Inland Rules state that when two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her starboard side (the give-way vessel) must keep out of the way and, if circumstances permit, cross behind the other vessel (the stand-on vessel).

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One way to remember this is that at night the give-way vessel will see the red (means danger) side light of the stand-on vessel and therefore must take action to pass astern. If you see a green side light, green means go, and you should maintain course and speed as the stand-on vessel.
The Meeting Situation
At times there may be some doubt whether the situation is a crossing or a head-on meeting. In case of doubt, you should assume that it is a meeting situation, in which neither vessel has a clear-cut "right-of-way," and each must act to avoid the other. Each vessel in a meeting situation must alter course to starboard so that each will pass on the port side of the other.

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At night, you will recognize a meeting situation if you simultaneous see a white bow light and both red and green side lights.
The Overtaking Situation
Any vessel overtaking any other vessel must keep out the way of the vessel being overtaken. The former is the give-way vessel and the latter is the stand-on vessel. This rule applies even if the overtaking vessel is propelled by wind, oars, or rubber band paddlewheel.
A vessel is deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft (behind) her beam. This is the angle prescribed by the stern light. At night, the overtaking vessel will see only the white stern light of the vessel being overtaken. If you see either side light, it is a crossing situation.

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The "Pecking Order"

There is a "pecking order" that can be used as a simplified memory aid to determine right of way for vessels of different types. Get very familiar with this list, as it is important to understand it thoroughly. The uppermost vessel on the list has right-of-way (stand-on vessel) over any vessel (give-way vessel) below it on the list:
  1. Overtaken vessel (top priority)

  2. Vessel not under command

  3. Vessel restricted in its ability to maneuver

  4. Vessel constrained by its draft

  5. Fishing vessel (commercial fishing or trawling but not trolling)

  6. Sailing vessel (engine not on)

  7. Power-driven vessel

International Rules

Once the intrepid mariner learns the Inland Rules, some things change when in international waters. This is the domain of the International Rules. While in "international rules waters," a vessel does not signal intent to pass on one side or the other, except when overtaking in a narrow channel.
Maneuvering and Warning Signals Under International Rules Whistle signals are sounded when vessels are in sight of each other and the following action is being taken:
one short blast means, "I am altering course to starboard"
two short blasts means, "I am altering my course to port"
These signals are not acknowledged by the other vessel. For the purpose of signaling, the term "short blast" means a blast on the ship's whistle of one second duration. The term "prolonged blast" means a blast of 4 to 6 seconds.

Sailing Vessels

Whether under inland or international rules, power vessels must keep clear of sailing vessels in open waters. A sailboat with motor running is defined as a motor boat. The "pecking order" between sailing vessels is more complex. When two sailing are approaching one another so as to involve risk of collision, one of then shall keep out of the way of each other as follows:
  • When each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other.
  • When both have the wind on the same side, the vessel which is to windward shall keep out of the way of the vessel which is to leeward.
  • If a vessel with the wind on the port side sees a vessel to windward and cannot determine with certainty whether the other vessel has the wind on the port or the starboard side, she shall keep out of the way of the other.
  • For the purposes of these rules the windward side shall be deemed to be the side opposite to that on which the mainsail is carried. On square-rigged vessels, it shall be deemed to be the side opposite to that on which the largest fore-and-aft sail is carried.


Now that you are familiar with "The Rules," go out and use them in passing, meeting, and crossing situations you find on the water. You will get many puzzled looks from inexperienced boaters with no training or testing.
Remember, if a collision does occur, your proper use of the correct signals and appropriate actions will win you points! But you know enough now to avoid a collision…