“Sail has right of way over power” is the one rule most people remember, and it is only partly true. The real rules are the International Regulations for Preventing Collisions at Sea (COLREGs), adopted in 1972 and used on the high seas and most coastal waters worldwide. Many countries apply them with local additions, and in the US the Coast Guard publishes them together with the Inland Rules in the Navigation Rules and Regulations Handbook.

Quick answer: a sailboat under sail alone is usually the stand-on vessel when meeting a powerboat, but it must keep clear of vessels that are not under command, restricted in their ability to maneuver, or engaged in fishing, and it must not impede large ships in narrow channels and traffic lanes. Any vessel overtaking another must keep clear. Between two sailboats, the boat on port tack gives way to the boat on starboard tack, and on the same tack the windward boat keeps clear. Once your engine is running and in gear, you are a power-driven vessel, even with the sails up.

The rules below summarize the international COLREGs. They are not a substitute for the full text, which every skipper should carry and read.

Stand-On vs Give-Way Vessels

The COLREGs avoid the phrase “right of way”. Instead, when two vessels risk collision, one is the give-way vessel and the other the stand-on vessel.

• Give-way vessel (Rule 16): must take early and substantial action to keep well clear. Make it obvious: a big alteration of course, a clear reduction of speed, or both. Rule 8 adds that a series of small alterations should be avoided because the other vessel may not notice them.
• Stand-on vessel (Rule 17): must keep its course and speed so the other vessel can predict it. If it becomes clear the give-way vessel is not acting, the stand-on vessel may maneuver to avoid collision; if collision can no longer be avoided by the give-way vessel alone, it must act.

Rule 2 sits above all of this: nothing in the rules excuses neglecting ordinary good seamanship. Being the stand-on vessel never gives you permission to hold course into a collision. Many accidents in our list of the most common sailing accidents start with someone assuming the other boat would move.

Sail vs Power: When Sailboats Have Right of Way (and When They Don’t)

Rule 18 sets a pecking order between types of vessel. Each vessel keeps out of the way of those below it in this list, which runs from most maneuverable to least:

Vessel type	Keeps clear of
Power-driven vessel underway	Sailing vessels, vessels engaged in fishing, restricted in ability to maneuver, not under command
Sailing vessel underway	Vessels engaged in fishing, restricted in ability to maneuver, not under command
Vessel engaged in fishing	Vessels restricted in ability to maneuver, not under command
Restricted in ability to maneuver / not under command	Each other according to the situation and good seamanship

Some definitions matter here:

• Sailing vessel: any vessel under sail, provided propelling machinery, if fitted, is not being used (Rule 3). Motorsailing makes you a power-driven vessel. In daylight a vessel under sail and power should show a cone, point down, in the rigging; the US Inland Rules exempt boats under 12 meters from the cone, but the international rules do not.
• Engaged in fishing: fishing with nets, lines or trawls that restrict maneuverability. A boat trolling a couple of lines is not “engaged in fishing” under the rules.
• Restricted in ability to maneuver (RAM): dredgers, cable layers, vessels towing that cannot deviate, vessels launching or recovering aircraft and similar.
• Not under command (NUC): a vessel that cannot maneuver because of an exceptional circumstance, such as steering or engine failure.
• Constrained by draft: under the international rules, vessels other than NUC and RAM should avoid impeding a deep-draft ship showing it is constrained by its draft. This category is not used in the US Inland Rules.

On top of the rules sits the informal “law of gross tonnage”: a container ship doing 20 knots cannot stop or turn in time to avoid a yacht, and from its bridge a small sailboat may be invisible under the bow. Whatever the rulebook says, get out of the way of big ships early. Our article on sailboat vs powerboat safety covers more of the practical risks.

Two Sailboats Meeting: Port/Starboard and Windward/Leeward

Rule 12 decides who gives way when two sailing vessels approach each other. The “tack” is named after the side the wind comes over: wind over the starboard side means starboard tack. For the purposes of the rule, the windward side is the side opposite to the one where the mainsail is carried (on a square-rigged vessel, the largest fore-and-aft sail).

1. Different tacks: the vessel on port tack keeps out of the way of the vessel on starboard tack.
2. Same tack: the windward vessel keeps out of the way of the leeward vessel.
3. Uncertain: if you are on port tack and see a sailboat to windward but cannot tell which tack it is on, assume you must keep clear.

Downwind this can be confusing because the boom may be on the “wrong” side when sailing by the lee or goosewinged. Go by where the mainsail is, not where you think the wind is. If you need a refresher on wind direction aboard, the masthead fly shows apparent wind, which is explained in true wind vs apparent wind. A simple habit: if you are on port tack, look under the jib for starboard-tack boats and plan to duck or tack early.

Overtaking Vessels

Rule 13 overrides the sail-versus-power and port-versus-starboard rules: any vessel overtaking another must keep out of the way until it is past and clear. A fast sailboat overtaking a slow trawler or a motorboat is the give-way vessel.

You are overtaking if you approach from more than 22.5° abaft the other vessel’s beam, the position from which at night you would see only its sternlight and neither sidelight. If in doubt, assume you are overtaking. A later change in bearing does not turn you into a crossing vessel with different obligations.

Narrow Channels and Traffic Separation Schemes

Narrow channels (Rule 9)

• Keep as near to the starboard side of the channel as is safe.
• A vessel under 20 meters or a sailing vessel shall not impede a vessel that can safely navigate only within the channel. In practice: stay out of the dredged channel when a ship is coming, and do not tack across in front of it.
• Do not cross a channel if doing so impedes a vessel that can only use the channel.
• Avoid anchoring in a narrow channel.

“Not impede” is stronger than give-way: you must act early enough that the ship never has to change course or speed because of you.

Traffic separation schemes (Rule 10)

Busy straits and port approaches, such as the Dover Strait, have traffic separation schemes (TSS) marked on charts as one-way lanes (see how to read a nautical chart). Small craft and sailing vessels must not impede power-driven vessels following a lane. If you need to cross, do so on a heading as close as practicable to a right angle to the traffic flow, even if the tide sets you diagonally, and cross as quickly as you can. Use inshore traffic zones where they exist. Planning a crossing like this is part of choosing the best time to cross the English Channel.

Ships, Fishing Vessels and Restricted Maneuverability

You can only follow Rule 18 if you can recognize these vessels. By day they show shapes: a black ball-diamond-ball for RAM, two balls for NUC, two cones point-to-point for fishing, and a cylinder for constrained by draft. At night they show specific light combinations, explained in our guide to sailboat navigation lights.

To judge whether a risk of collision exists, use Rule 7: take compass bearings of the approaching vessel. If the bearing does not change appreciably as the range closes, a risk of collision exists. With very large ships, even a slowly changing bearing can be dangerous at close range. AIS and radar help, but they do not replace a proper lookout (Rule 5).

Sound Signals and Avoiding Collisions

Maneuvering and warning signals

Under the international rules, maneuvering signals (Rule 34) are made by power-driven vessels in sight of one another. A short blast lasts about one second; a prolonged blast four to six seconds.

Signal	Meaning (international)
1 short	I am altering my course to starboard
2 short	I am altering my course to port
3 short	I am operating astern propulsion
5 or more short and rapid	I do not understand your intentions / doubt that you are taking sufficient action (any vessel may use it)
1 prolonged	Approaching a bend or obstruction where other vessels may be hidden

In the US Inland Rules, the one- and two-blast signals mean “I intend to leave you on my port side” or “…on my starboard side” for meeting and crossing vessels, and the other vessel answers with the same signal to agree. That is a key difference from the international rules, where the signal announces an action being taken. On the Great Lakes, Western Rivers and other designated waters, a power-driven vessel going downbound with a following current also has the right of way over an upbound vessel in narrow channels.

Restricted visibility

In fog there is no stand-on or give-way vessel (Rule 19). Every vessel proceeds at a safe speed and avoids close-quarters situations. A sailing vessel underway sounds one prolonged blast followed by two short blasts at intervals of no more than two minutes; a power-driven vessel making way sounds one prolonged blast. Avoid turning to port for a vessel detected ahead of the beam, and avoid turning toward a vessel abeam or abaft the beam.

Racing Rules Are Different

Boats racing against each other follow World Sailing’s Racing Rules of Sailing, which share the port/starboard and windward/leeward principles but add rules for mark-room, tacking and penalty turns. Between a racing boat and a vessel that is not racing, the COLREGs apply. If you join a club race or regatta, read the sailing instructions, which may also specify how the COLREGs apply at night.

Right of Way Rules: Summary

• There is no absolute right of way, only stand-on and give-way duties, and everyone must avoid collision.
• Power gives way to sail, but sail keeps clear of fishing, RAM and NUC vessels and must not impede ships in channels and traffic lanes.
• Port tack gives way to starboard tack; windward gives way to leeward; overtaking vessels always keep clear.
• A sailboat with its engine in gear is a power-driven vessel.
• Act early and obviously, check bearings, and keep a proper lookout.
• Know the local rules: US Inland Rules, river rules and harbor bylaws can differ from the international regulations.

If you are new to all this, the sailing tips for beginners guide is a good companion; practice identifying stand-on and give-way situations every time you are out, and the rules soon become second nature.