Paragraph (a): Determining risk
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.
COLREGs trainerPart B: Steering and Sailing Rules
Rule 7
Risk of Collision
Use all available means to determine if risk of collision exists; if in doubt, it does.
Wording follows the International Regulations as printed in the US Coast Guard Navigation Rules handbook (2024), with British spelling, and is shortened in places. Download the rules
Read the whole of Rule 7 on one page
Paragraph (a): Determining risk
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.
Paragraph (b): Use of radar
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.
Paragraph (c): Scanty information
Assumptions shall not be made on the basis of scanty information, especially scanty radar information.
Paragraph (d): Considerations
(i) 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 with an appreciable bearing change, particularly when approaching a very large vessel or a tow, or when approaching a vessel at close range.
A training aid, not the official text. The COLREGs are an IMO convention, and your national authority publishes the version that applies in its waters. Check the rules themselves before you rely on them at sea. Download the rules.