Skippers who can spin their boat on a sixpence, moor alongside under sail in the teeth of an offshore gale and fix their position without instruments in fog so thick they can’t see their own bow might still fear one aspect of a Yachtmaster exam: the interrogation about their knowledge of the International Regulations for Preventing Collisions at Sea. So we’ve tried to break down the COLREGs into bite-size pieces that are easy to learn and understand, and to help you find any rule that you want to check, quickly and easily.

First, the bad news. The COLREGs are split into five parts, 38 rules and four annexes (each containing several points), and if you are a Yachtmaster candidate you are going to be asked questions about the content. Now the good news. you don’t need to quote each rule word for word (unless you are taking an MCA Officer of the Watch exam or similar).

We’ll take a closer look at the essentials of the rules in a moment. First, click on this paragraph to download your copy of COLREGS. It’s impossible to avoid the dry technicalities and legalese of the text, but we’ve opted to present it in a simple layout that should make it easy for you to find the sections that you need.

Got your copy of the rules? Okay, let’s begin.

Part A. Rules 1-3

Explains where and how the rules apply, and gives definitions of various terms. The only rule you need to fix in your mind from Part A is Rule 2. In our opinion, this is the most important. In essence, it says that if you are ever in a situation when you have to choose between following the rules or taking action to avoid a collision, you must take action. Sounds like common sense – do all you can to avoid smacking into the boat in front of you! Keep in mind the tale of Captain Grey, who died defending his right of way. He was right, dead right, as he sailed along, but he’s just as dead as if he’d been wrong.

Part B. Rules 4-19

Part B is the meat of the COLREGs as far as Yachtmaster candidates are concerned. It’s split into three sections, the most important parts of which from the perspective of your exam are listed below.

Section 1

Applies to all vessels at all times, in all conditions of visibility.

Rule 5, keep a lookout. In other words, if you’re single-handed don’t nip down to make lunch when you’re crossing a TSS.

Rule 6, safe speed. You must be able to “take proper and effective action to avoid collision and be stopped within a distance appropriate to the prevailing circumstances and conditions”. If you don’t know how to assess that, the rule goes into more details. Check your copy of COLREGs now.

Rule 7, assessing risk of collision. How to work out if that tanker on the horizon is likely to smash you and your yacht into a mess of bloody fibreglass, sailcloth and bone. The key takeaway here is the phrase “every vessel shall use all available means appropriate to the prevailing circumstances and conditions to determine if risk of collision exists. If there is any doubt such risk shall be deemed to exist”.

Rule 8, avoiding collision. Most important here is that any action you take to avoid being smashed into a mess of bloody fibreglass, sailcloth and bone must be “positive, made in ample time and with due regard to the observance of good seamanship”.

Rule 9, narrow channels. Of importance to most skippers will be the phrase “a vessel of less than 20 metres in length or a sailing vessel shall not impede the passage of a vessel which can safely navigate only within a narrow channel or fairway”. Basically, keep out of the way.

Rule 10, traffic separation schemes. Don’t cross them unless you must. And if you must, cross them at 90 degrees to the flow of traffic – whatever the wind and tide are doing.

Section 2

Applies to vessels that can see each other. This section is all about the specifics of actions to be taken to avoid collisions, and who has right of way. If you learn no other section of COLREGs by heart, it’s worth learning this section.

Rule 12, sailing vessels. The position of your boat in relation to the wind will decide if you have to give way or maintain course and speed when you meet another sailing vessel.

Rule 13, overtaking. If you can or would be able to see only the other boat’s stern light, you’re overtaking. Otherwise, you’re passing.

Rule 14, head-on. Don’t panic and start yelling “brace, brace, brace”. Just turn to starboard. Assuming the other skipper does the same you’ll both live to sail another day. If you turn to port, you’ll go to court (unless you’re taking action to avoid collision with that idiot overtaking on your starboard quarter).

Rule 15, crossing. If you can see the other boat’s red port light, keep out of the way. If you can see the green starboard light, you’re good to go. Red, stop. Green, go. Simple.

Rules 16 and 17, actions of give-way and stand-on vessels. If you’re the give-way vessel, make sure you do something to keep out of the way. If you’re the stand-on vessel, keep doing what you’re doing (but remember Rule 2).

Rule 18, responsibilities between vessels. Basically, the pecking order. If you’re a sailboat, you can expect most power-driven vessels to keep out of your way. But not always.

Section 3

There’s only one rule in this section, but it’s extremely important…

Rule 19, restricted visibility. You WILL be asked about this one if you’re taking a Yachtmaster exam. The key points are i) keep a good watch with eyes, ears, and any electronics you may have on board (check Rule 5), ii) maintain a safe speed (check Rule 6), assess the risk of collision (check Rule 7), iii) use your sound signals (click here to see our tutorial on sound signals for manoeuvring and fog), iv) take action (check Rules 12-15), and remember that there is no give-way/stand-on vessel in fog. ALL vessels must give way as appropriate.

Part C. Rules 20-31

This part is all about the lights and shapes that vessels must display. Want to know how far your lights must shine? Check Rule 22. Rule 23 deals with lights and shapes for power vessels, Rule 24 concerns towing vessels, and Rule 25 is for sailboats. Rules 26-31 are about fishing vessels, boats not under command, vessels restricted in their ability to manoeuvre, vessels constrained by draught, pilot boats, vessels at anchor or aground (you will need to know the lights and shapes for all of these) and seaplanes.

Part D. Rules 32-37

Part D of COLREGs concerns sound and light signals. Make sure in particular that you understand Rule 34 (sounds for manoeuvring) and Rule 35 (sound signals in fog). Click here to check our tutorial on sound signals.

Part E. Rule 38

Exemptions, or when the rules don’t apply. Unless you’re taking an MCA exam, don’t worry too much about this.


Annex I contains technical details for lights and signal shapes on boats. It’s mostly in-depth and specialised stuff. However, Yachtmaster examiners for some reason love to ask about the angle of visibility of lights. It’s easy to remember if you think of the boat as a circle of 360 degrees. The stern light must be visible at 135 degrees, so any light or combination of lights facing forward must add up to 225 degrees (360-135=225). Port and starboard lights must each be visible at 112.5 degrees (112.5×2=225), and a steaming light must be visible at 225 degrees.

Annex II deals with additional signals for different kinds of fishing vessels – for example the lights on a trawler when it’s shooting or hauling nets, or when the net is stuck.

Annex III is another technical one. This time, it’s all about the mechanics of your sound signalling equipment.

Annex IV covers distress signals. We all know SOS and flares, but there are in fact 17 recognised distress signals. You’ll be expected to know most of them.

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