COLREGS – International Regulations for Preventing Collisions at Sea

Question MarkHere’s an interesting vignette to help you consider a right-of way situation we found on The Log – California’s Boating & Fishing News. We frequently test each other when encountering another vessel…and we’re finding that we’re not as confident about the rules as we should be.

Here’s the actual COLREGS page off the IMO Website.


Recreational Sailboat vs. Tugboat with Barge: Who Has the Right of Way?

Posted: November 6, 2013  |  By: David Weil, Esq.

I own a sailboat that I keep at a marina in San Diego. We had an encounter in the bay last month with a tugboat that was pushing a barge, and there was some disagreement among our crew as to who had the right of way. We were making way under sail only — and, as such, I believe that we had the right of way over the tug, which is basically just a power boat. Several of my crew are under the impression that the tug had the right of way since, as a commercial vessel underway with a barge, it would be considered a “restricted” vessel under the Rules of the Road. Which of us has the correct answer?

All mariners should be familiar with the Rules of the Road (otherwise known, in navigable ocean waters, as the International Regulations for Preventing Collisions at Sea, or “COLREGS”).  For the most part, the Rules are clearly written and unambiguous, and we should therefore be able to point to a simple answer to our reader’s question.

Life is rarely that simple, but at the outset we can make one very clear observation: Contrary to the understanding of a lot of recreational boaters, there is no specific provision of the Rules that requires a recreational vessel to give way to a commercial vessel.

Unfortunately things get pretty complicated after we make that observation.

Throughout the world, the Rules operate under a body of maritime law that deals with collisions at sea. Under that system, the burden for safety at sea is shared by all mariners, and liability for damage caused by a collision will be allocated among the various parties according to their percentage of fault, as determined by a court.

The circumstances vary considerably from case to case, and the outcome will depend upon what expert witnesses have to say about the actions of the parties. This is the umbrella under which all cases like this will be evaluated. And, with that in mind, we can look at our reader’s concerns.

Our analysis begins in Section II of the Rules — “Conduct of Vessels in Sight of One Another.” Section II, Rule 18(a) states that “except where Rules 9, 10 and 13 otherwise require, a power-driven vessel underway shall keep out of the way of a sailing vessel.”

Rules 9 and 10 refer to large ships operating within a narrow channel or inshore shipping lane, where the large ships are expressly given the right of way. A tugboat, with or without a barge, is not considered a big ship, and it does not operate under those rules.

Rule 13 applies when a vessel is overtaking another vessel, in which case, the vessel being overtaken has the right of way, whether it is a powerboat or a sailboat.

Rule 18, therefore, provides the authority for the commonly accepted understanding that sailboats have the right of way over powerboats. But is there a special rule that applies to certain types of power-driven vessels? In some circumstances, yes.

Rule 18(b) requires a sailing vessel to keep out of the way of (i) a vessel not under command; (ii) a vessel restricted in her ability to maneuver; and (iii) a vessel engaged in fishing.” A vessel not under command is basically a vessel adrift with a mechanical problem, and a tugboat is obviously not engaged in fishing, so the only question is whether a tugboat with a barge could be characterized as a vessel “restricted in her ability to maneuver.”

Rule 3(g) defines a “vessel restricted in her ability to maneuver” as a “vessel which from the nature of her work is restricted in her ability to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel.”

A dredge that is currently engaged in dredging operations provides the most common example of a “restricted” vessel. But is a tug with a barge a restricted vessel?

Believe it or not, the answer is generally “no,” but we don’t have to guess. The Rules require these vessels to display lights (at night) and day shapes (during daylight hours) to identify their status.

Rule 27(b) requires a restricted vessel to exhibit: “(i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white; and (ii) three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond.”

So, the “short” answer to our reader’s question is that his sailboat has the right of way over the tug, unless the tug is exhibiting the lights or day shapes for a restricted vessel. But our analysis is still not over.

All of the Rules operate under the umbrella of Rule 2. Specifically Rule 2(b), which provides that “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.”

As a consequence of Rule 2 and of the maritime law system of allocating fault between vessels, any boat that stubbornly insists on a super-technical adherence to the other rules will be found to have contributed to the collision, and in some circumstances may be found to bear the majority of fault.

So, for our readers who are still with us (and have not fallen asleep), here is what we should take from this analysis. Technically, a sailboat has the right of way over a commercial vessel, unless that vessel is a big ship or it is displaying the lights or shapes of a “restricted” vessel.

As such, commercial vessels should do their best to stay out of the way of sailboats.  But this is not always possible, and sailboat operators need to stay diligent around commercial vessels and take steps to avoid collision when it appears that the commercial vessel will be unable to stay clear.

 David Weil is licensed to practice law in the state of California and, as such, some of the information provided in this column may not be applicable in a jurisdiction outside of California. Please note also that no two legal situations are alike, and it is impossible to provide accurate legal advice without knowing all the facts of a particular situation. Therefore, the information provided in this column should not be regarded as individual legal advice, and readers should not act upon this information without seeking the opinion of an attorney in their home state. 

 David Weil is the managing attorney at Weil & Associates ( in Long Beach. He is an adjunct professor of Admiralty Law at Loyola University Law School, is a member of the Maritime Law Association of the United States and is former legal counsel to the California Yacht Brokers Association. He is also one of a small group of attorneys to be certified as an Admiralty and Maritime Law Specialist by the State Bar of California. If you have a maritime law question for Weil, he can be contacted at (562) 438-8149 or at

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