COLREGs Rule 12: Right-of-way between two sailing vessels

Last reviewed: October 14, 2026

Rule 12 covers two sailing vessels approaching one another so as to involve risk of collision. One of them must keep out of the way, depending on which side each has the wind. The rule also says how to decide which side is the windward side.

Applies toTwo sailing vessels approaching one another so as to involve risk of collision.

What it says

  1. When two sailing vessels approach one another so as to involve risk of collision, one of them must keep out of the way of the other.

    COLREGs Rule 12(a)“When two sailing vessels are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other as follows:”

  2. When each vessel has the wind on a different side, the vessel with the wind on the port side must keep out of the way of the other.

    COLREGs Rule 12(a)(i)“When each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other.”

  3. When both vessels have the wind on the same side, the vessel to windward must keep out of the way of the vessel to leeward.

    COLREGs Rule 12(a)(ii)“When both have the wind on the same side, the vessel which is to windward shall keep out of the way of the vessel which is to leeward.”

  4. A vessel with the wind on the port side that sees a vessel to windward and cannot determine with certainty which side the other vessel has the wind on must keep out of the way of the other.

    COLREGs Rule 12(a)(iii)“If a vessel with the wind on the port side sees a vessel to windward and cannot determine with certainty whether the other vessel has the wind on the port or on the starboard side, she shall keep out of the way of the other.”

  5. For this Rule, the windward side is the side opposite the side on which the mainsail is carried. For a square-rigged vessel, it is the side opposite the side on which the largest fore-and-aft sail is carried.

    COLREGs Rule 12(b)“the windward side shall be deemed to be the side opposite to that on which the mainsail is carried or, in the case of a square- rigged vessel, the side opposite to that on which the largest fore-and-aft sail is carried.”

  6. Inland: A vessel restricted in her ability to maneuver while engaged in an operation to maintain safety of navigation in a traffic separation scheme is exempt from this Rule to the extent necessary to carry out the operation.

    COLREGs Rule 12(k)“A vessel restricted in her ability to maneuver when engaged in an operation for the maintenance of safety of navigation in a traffic separation scheme is exempted from complying with this Rule”

  7. Inland: A vessel restricted in her ability to maneuver while laying, servicing, or picking up a submarine cable within a traffic separation scheme is exempt from this Rule to the extent necessary to carry out the operation.

    COLREGs Rule 12(l)“A vessel restricted in her ability to maneuver when engaged in an operation for the laying, servicing, or picking up of a submarine cable, within a traffic separation scheme, is exempted from complying with this Rule”

Common questions

Which sailing vessel keeps clear when the wind is on different sides?

The vessel that has the wind on the port side must keep out of the way of the other.

“When each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other.”

Who gives way when two sailing vessels have the wind on the same side?

The vessel to windward must keep out of the way of the vessel to leeward.

“When both have the wind on the same side, the vessel which is to windward shall keep out of the way of the vessel which is to leeward.”

How is the windward side determined under Rule 12?

The windward side is the side opposite the one on which the mainsail is carried. For a square-rigged vessel, it is opposite the side with the largest fore-and-aft sail.

“the windward side shall be deemed to be the side opposite to that on which the mainsail is carried or, in the case of a square- rigged vessel, the side opposite to that on which the largest fore-and-aft sail is carried.”

The text of COLREGs Rule 12

U.S. Coast Guard, Navigation Rules and Regulations Handbook

Rule 12: Sailing Vessels

International (COLREGs)

(a) When two sailing vessels are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other as follows:

(i) when each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other;

(ii) when both have the wind on the same side, the vessel which is to windward shall keep out of the way of the vessel which is to leeward;

(iii) if a vessel with the wind on the port side sees a vessel to windward and cannot determine with certainty whether the other vessel has the wind on the port or on the starboard side, she shall keep out of the way of the other.

(b) For the purposes of this Rule the windward side shall be deemed to be the side opposite to that on which the mainsail is carried or, in the case of a square- rigged vessel, the side opposite to that on which the largest fore-and-aft sail is carried.

Inland Rules

(k) A vessel restricted in her ability to maneuver when engaged in an operation for the maintenance of safety of navigation in a traffic separation scheme is exempted from complying with this Rule to the extent necessary to carry out the operation.

(l) A vessel restricted in her ability to maneuver when engaged in an operation for the laying, servicing, or picking up of a submarine cable, within a traffic separation scheme, is exempted from complying with this Rule to the extent necessary to carry out the operation. Conduct of Vessels in Sight of One Another Sailing vessels

(a) When two sailing vessels are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other as follows:

(i) When each has the wind on a different side, the vessel which has the wind on the port side shall keep out of the way of the other.

(ii) When both have the wind on the same side, the vessel which is to windward shall keep out of the way of the vessel which is to leeward.

(iii) If a vessel with the wind on the port side sees a vessel to windward and cannot determine with certainty whether the other vessel has the wind on the port or on the starboard side, she shall keep out of the way of the other.

(b) For the purpose of this Rule, the windward side shall be deemed to be the side opposite to that on which the mainsail is carried or, in the case of a square- rigged vessel, the side opposite to that on which the largest fore-and-aft sail is carried.

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of August 12, 2024. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.