COLREGs Rule 7: Determining risk of collision

Last reviewed: October 14, 2026

Rule 7 covers how a vessel decides whether risk of collision exists. Every vessel must use all available means appropriate to the prevailing circumstances and conditions. If there is any doubt, risk is deemed to exist.

Applies toEvery vessel.

What it says

  1. Every vessel must use all available means appropriate to the prevailing circumstances and conditions to determine if risk of collision exists.

    COLREGs Rule 7(a)“Every vessel shall use all available means appropriate to the prevailing circumstances and conditions to determine if risk of collision exists.”

  2. If there is any doubt, risk of collision is deemed to exist.

    COLREGs Rule 7(a)“If there is any doubt such risk shall be deemed to exist.”

  3. Proper use must be made of radar equipment if it is fitted and operational. This includes long-range scanning to obtain early warning of risk of collision.

    COLREGs Rule 7(b)“Proper use shall be made of radar equipment if fitted and operational, including long-range scanning to obtain early warning of risk of collision”

  4. Assumptions must not be made on the basis of scanty information, especially scanty radar information.

    COLREGs Rule 7(c)“Assumptions shall not be made on the basis of scanty information, especially scanty radar information.”

  5. Risk of collision is deemed to exist if the compass bearing of an approaching vessel does not appreciably change.

    COLREGs Rule 7(d)(i)“such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change;”

  6. Risk of collision may sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow, or a vessel at close range.

    COLREGs Rule 7(d)(ii)“such risk may sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow or when approaching a vessel at close range.”

Common questions

What if I am unsure whether risk of collision exists?

If there is any doubt, risk of collision is deemed to exist.

“If there is any doubt such risk shall be deemed to exist.”

Does a steady compass bearing mean risk of collision?

Yes. Risk of collision is deemed to exist if the compass bearing of an approaching vessel does not appreciably change.

“such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change;”

Can risk of collision exist if the bearing is changing?

Yes, it may sometimes. This is particularly so when approaching a very large vessel, a tow, or a vessel at close range.

“such risk may sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow or when approaching a vessel at close range.”

When does Rule 7 require radar use?

Proper use must be made of radar equipment if it is fitted and operational. The rule does not require radar on a vessel that does not have it fitted and operational.

“Proper use shall be made of radar equipment if fitted and operational, including long-range scanning to obtain early warning of risk of collision”

The text of COLREGs Rule 7

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

Rule 7: Risk of Collision

(a) 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. (b) Proper use shall be made of radar equipment if fitted and operational, including long-range scanning to obtain early warning of risk of collision and radar plotting or equivalent systematic observation of detected objects. (c) Assumptions shall not be made on the basis of scanty information, especially scanty radar information. (d) In determining if risk of collision exists the following considerations shall be among those taken into account: (i) such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change; (ii) such risk may sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow or when approaching a vessel at close range.

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.