Understanding the Navigation Rules (COLREGS)

1. What Are the COLREGS?

The International Regulations for Preventing Collisions at Sea (COLREGS) were first established in 1972 by the International Maritime Organization (IMO) and have since been adopted by nearly every maritime nation. In North America, they are enforced through national versions:

• In Canada: under the Collision Regulations of the Canada Shipping Act

• In the United States: through the Navigation Rules, International–Inland

These regulations provide a universal language for how vessels should behave when meeting, crossing, or overtaking one another — no matter where in the world they are.

At their core, the COLREGS are about predictability. When everyone follows the same patterns, you can anticipate what another vessel will do and take early, clear action to avoid danger.

2. The “Rules of the Road” on Water

Think of the COLREGS as the maritime version of highway traffic laws. On the road, everyone knows which side to drive on, who yields, and when to stop. On the water, we use navigation rules to achieve the same clarity.

These rules specify:

• Right-of-way (stand-on) and give-way responsibilities

• Safe speeds and proper lookout

• Lighting, sound signals, and day shapes

• Conduct in restricted visibility

Let’s look at the main principles every recreational boater should know.

3. Rule 5 — Always Maintain a Proper Lookout

Every vessel must maintain a proper lookout by sight and hearing at all times. That means continuously scanning the horizon for other boats, buoys, swimmers, and hazards — even when using radar or GPS.

Distractions are a leading cause of boating accidents. Assign one person to watch forward and another to check astern if possible. Listen for engine sounds, horns, or breaking waves that might indicate another craft approaching. Technology helps, but human attention is irreplaceable.

4. Rule 6 — Safe Speed

A safe speed allows you to take effective action to avoid collision and to stop within a distance appropriate to the conditions.

Factors to consider include:

• Visibility (day, night, fog, or glare)

• Traffic density

• Background lights near shore

• The vessel’s maneuverability and stopping distance

• Wind, current, and wave conditions

There’s no specific speed limit on open water — “safe speed” depends on conditions. However, most marinas and canals have posted limits (usually 5–10 knots). If you create a wake that endangers others or causes property damage, you are likely going too fast.

5. Rule 7 — Assessing the Risk of Collision

Never assume another vessel sees you or will alter course. The rule says you must use all available means — sight, hearing, radar, AIS, and judgment — to determine if a collision risk exists.

A simple visual method:
Pick a stationary reference on your boat (like a rail) and line it up with the approaching vessel. If that vessel stays in the same relative position while getting larger, you are on a collision course.

When in doubt, take early and bold action to avoid danger — small, hesitant course changes are confusing.

6. Rule 8 — Action to Avoid Collision

If a risk of collision exists, act in ample time and make your maneuver large enough to be obvious to the other vessel. Small course changes are harder to detect.

• Change direction or speed decisively.

• Avoid passing too close.

• Once clear, return to your original course only when it’s safe.

Sudden zigzags or panic reversals can make things worse. Calm, predictable action is key.

7. Rules 9–10 — Channels and Traffic Lanes

When navigating in a narrow channel, keep as far to the starboard (right) side as is safe. Small boats should not impede larger vessels constrained by draft (e.g., cargo ships).

In Traffic Separation Schemes (used in busy sea lanes), follow the designated lanes just like cars on a divided highway. Cross them at right angles if necessary, and avoid anchoring inside them.

For recreational boaters, this means staying clear of shipping channels whenever possible.

8. Rules 11–18 — The Core Steering and Sailing Rules

These are the heart of collision avoidance. They define what to do when meeting another vessel:

a. Meeting Head-On

When two power-driven vessels approach each other head-on or nearly so, each shall alter course to starboard (right) so that they pass port-to-port (left-to-left).
👉 Think: “Keep right” — just like driving a car.

b. Crossing Situations

When two power-driven vessels are crossing, the vessel that has the other on its starboard (right) side must give way.

• The give-way vessel should slow down or steer clearly behind the other.

• The stand-on vessel should maintain course and speed but stay alert in case the other fails to act.

A simple memory trick: “If the other boat is on your right, they have the right of way.”

c. Overtaking

Any vessel overtaking another (approaching from more than 22.5° abaft the beam — roughly behind the side) is the give-way vessel, regardless of type. The overtaking boat must keep clear until fully past and safely ahead.

The vessel being overtaken should maintain course and speed but remain alert.

d. Power vs. Sail

A sailing vessel under sail alone has right of way over a power-driven vessel, because it has less ability to maneuver quickly. However, if the sailboat is using its engine, it counts as a power-driven vessel and must follow those rules.

e. Vessels Restricted in Ability to Maneuver

Certain vessels (such as those engaged in fishing, towing, dredging, or constrained by draft) have priority because they can’t easily alter course. Recreational boats should keep clear whenever possible.

10. Rule 34 — Sound and Light Signals

Sound signals are the “turn signals” of the waterway. In narrow channels or restricted visibility, they communicate intention:

Recreational vessels should also carry a whistle or horn capable of producing these blasts. In Canada and the U.S., this is a legal requirement for all boats over a certain size.