Collision Regulations & Rules

"Here lies the body of Michael O'Day,
who died maintaining the right of way.
He was right, dead right, as he sailed along,
but he's just as dead as if he'd been wrong."

There is no such thing as a right-of-way. There is only Rules of the Road - all boat operators must use every available means (lookout, radar, radio) to determine whether there is a risk of collision, and avoid one.

All ships (vessels over 20 metres / 65 ft.) have the right of passage over all boats under 20 metres. For pleasure craft, power-boats must keep clear of boats being sailed, rowed or paddled. (A sailboat under sail and power is considered a power-boat.) In a narrow channel, boats must not hamper the safe passage of any vessel that cannot safely navigate outside the channel. There are additional rules for the Heritage Canals

Rules for Power-boats

Put your mouse over each image to view the correct action to avoid a collision.

Both alter course
Meeting head-on: When two boats meet head on, each must alter course to starboard (right) to pass. A sound signal of 1 short blast meaning "I am altering course to starboard" (I intent to pass you on the port side). The other boat repeats the signal to indicate "understood". If you must pass starboard to starboard, indicate your intentions clearly (sound 2 short blasts). [sound signals] View answer

Give way to the vessel on your starboard
Crossing on a collision course: When on a collision course - the relative direction of the other boat will appear not to change - boat A on the left must give-way or keep clear of boat B. At night, A will see B's red light; B will see A's green light. To avoid collision, A must turn right to pass behind B, slow down, stop or reverse. View answer

Stay clear when passing
Overtaking: When boat A overtakes boat B running in the same direction, A must stay clear of B, while passing on either side. A may use sound signals to indicate passing on B's starboard side, or 2 short blasts to pass on B's port side. View answer
Bowfront of the boat
Sternback of the boat
Portleft side of the boat, where the red light is located
Starboardright side of the boat, where the green light is located
Windward side opposite to that on which the mainsail is carried
Port sectorFrom Dead ahead to 22.5 degrees abaft the port beam (unbroken arc of 112.5 degrees from the bow) - the red light shows in this sector.
Starboard sectorFrom Dead ahead to 22.5 degrees abaft the starboard beam - the green light shows in this sector.

Since Teutonic times boats had a steering oar, or board on the right side of the hull near the stern. To land at a dock one needed to keep the oar free and away from the dock so port was on the opposite side of the STEERING BOARD - Starboard. (Oxford etymological dicionary)

Starboard is generally accepted to be a corruption of steer-board, the board or oar which projected into the sea from the starboard side of old vessels and by which they were steered before the invention of the hanging rudder. (Oxford Companion to Ships and the Sea)

Rules of the Road

You must always try to avoid a collision regardless of the "rules of the road".

  1. All boats must keep out of the way of any vessel fishing with nets, lines, or trawls (they must show appropriate shapes or lights to indicate this activity), Boats fishing or trolling with a line, which does not restrict its manoeuvrability, must follow the same rules as any other pleasure craft.
  2. Keep out of the way of all ships over 65 feet (20 metres), even if you are sailing.
  3. If a power-boat approaches within your port sector, maintain your course and speed with caution.
  4. If a vessel approaches within your starboard sector, keep out of its way (see sailboat exception), altering course early to indicate you are passing on its stern.
  5. If two vessels approach head-on, they each alter course to starboard and pass port-to-port.
    [Sound signal of one blast indicates altering to starboard. Other vessel returns the same signal to acknowledge, or 5 blasts to indicate a problem. More...]
  6. Any vessel overtaking another must keep clear.
    [This applies to a sailboat passing a powerboat -- it does happen! Sound signals should be used. It is considered good boat ettiquette to slow while the other vessel passes you if that vessel has come down off plane "properly" -- directly aft -- to pass you.]
  7. A power-boat keeps clear of a sailboat under sail.
    [Note that a powerboat passing a sailboat can knock the wind right out of its sails from the wake, causing the boat to change course unexpectedly.]
  8. Give way to boats not under command or restricted in their ability to maneuver (narrow channels, traffic lanes).
  9. Seaplanes must take off and land without causing any danger of collision.

From the Canada Shipping Act: Collision Regulations:
Any action taken to avoid collision shall, if the circumstances of the case admit, be positive, made in ample time and with due regard to the observance of good seamanship.

Shoreline speed limits in most provinces restricts boats to 10 km/h within 30 metres (100 feet) of shore. There are some exemptions, such as ski boats going perpendicular (directly away) from shore. (Speed Limits & Boat Wakes)


The Rules of the Road began in the days when most ships had square rigs and had trouble sailing to windward. The rules made the downwind boat "give way" to those sailing to windward, the "privileged" boat.

Tack is determined by the mainsail. For example, port tack means that the wind is coming over the port side (left side facing forward) of the boat and the mainsail (or largest foresail) is carried to starboard. The port side is thus the windward side.

Racing rules apply only to the race and does not provide special exemption from the international rules when meeting non-racing boats.

  1. Starboard tack rule: A sailboat with the wind on the port side (port tack) shall keep out of the way of a sailboat with the wind on the starboard side (starboard tack).
  2. Windward rule: A sailboat on the same tack but to windward shall keep clear of a sailboat which is to leeward. [This means a boat sailing downwind must alter course to avoid a boat sailing upwind on the same tack. Older books say "a vessel which has the wind aft shall keep out of the way of the other vessel."]
  3. A sailboat on a port tack that sees a sailboat to windward and cannot determine which tack it is on, shall keep clear of the other.

Alter course well in advance so the other vessel knows your intentions. There's no such thing as "right of way" on the water, only "rules". Don't assume the other vessels knows the rules.

From the Online Forums

Serious stories told with humour

Steam giving way to sail is more acknowleged in the thingy than the observation, one recals going up the St Lawrence Sea Way through a area called Thousand Islands,driving five thousand tons of Doxford driven steel when this theory was sorely tried,a Glasweigian ships Captain hurling abuse and turning the air blue through a loud hailer tended to shift the little buggas though.

"If yon buggah disnae move laddie, run im down, he shudnae be in the shipping channel"
What Mr. Draper says about steam yielding to sail is more theory that fact is very true. I was on the S.S. Norway standing on a platform above the bridge as we were leaving Miami Harbor and observed a 30 foot sailboat, under sail, tacking in front of 'Norway' while we were still in the channel.

Now one must remember that at this time the S.S. Norway (formerly know as the S.S. France) was the largest cruise ship in the world. Another fact to remember is that there is only 6 to 3 feet clearance between the bottom of the channel and the keel of the ship when it is in the center of the shipping channel of Miami Harbor. So here we are (we being the 'Norway') slowly going out to sea weighing about 200 gazillion tons and this sailboat is acting like he is going test the rules of the roads.

By no means is our intrepid sailor alone in the channel, there were many pleasure boats, large and small, moving up and down the channel, on the edges where any small boater with any sense would be when a ship the size of the Empire State Building is coming down a narrow channel. All of these other boats were sounding their horns, yelling and pointing behind our clueless sailor. Trying to get his attention about the behemoth bearing down on him. He just sits there in the cockpit with his yachting cap on sailing away.

This guy is so totally clueless he is waving back at all the boats and people trying to get his attention. I mean folks driving on the street next to the channel are honking their horns to get his attention. Now I am starting to get concerned, the adult alcoholic beverage I am drinking is getting low and I do not want to leave my perch to go get another drink because I might miss the action. The sailboat is now starting to disappear under the bow of our ship.

About this time the young chap wearing two strips on his shoulders who is standing on the port bridge picks up a phone and calls somebody. A few seconds later this gent with four strips and a star on his shoulder wanders out on the port bridge, stops, looks and turns back and says something to the effect of, 'First Mate please hoot the hooter as I do not want to scratch the paint on our bow.'

No sooner said than done, the ship's horn bellows a mighty blast lasting about two or three seconds (it could have been longer than that, I lost my hearing at that point because I was standing directly below the forward stack where the horns were attached).

Our sailor at this point turns and looks back, I can only imagine what his view was, and sees this huge blue hull bearing down on him. Anyway, he throws his rudder hard to port and scuttles out of the way.

Our Captain watches the sailboat head for the shore, shakes his head and goes back into the bridge.

So I can tell one thing about ship's horns. When you're in a little sailboat and you hear one long blast, watch out!

P.S. got my hearing back, took a few adult beverages however. (2004)
Some Trivia: "If two lights you see ahead, port your helm and show your red."
When the movie "Titanic" came out, there were many complaints that the helmsman was wrongly instructed to turn to port with the command 'Hard a starboard', but this was correct in 1912 when the Titanic sailed. Until about 1937 to "port your helm" meant pushing a tiller to port, which would turn the rudder and vessel to starboard. Even after ships had wheel steering, commands continued to use the tiller comvention until they were reversed around 1937.

One dock rat informed us that an international marine tribunal decided there would not be enough time to change helm commands all at once, so they decided instead to change helm commands on navy ships one year and commercial ships the next and the yotties were left to decide on their own... {ok it's a joke}

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