Rule 5 Flashcards
What is Rule 5 of COLREGs?
Rule 5 states that every vessel must maintain a proper lookout by sight, hearing, and all available means to detect risks and avoid collisions.
Why is a proper lookout important?
A proper lookout ensures early detection of risks like other vessels, floating debris, or navigational hazards, preventing collisions and ensuring safety at sea.
What does ‘all available means’ in Rule 5 include?
It includes sight (visual observation), hearing (sound signals), and equipment like radar, ARPA, AIS, ECDIS, and binoculars.
When is maintaining a proper lookout especially critical?
In restricted visibility, congested traffic areas, during nighttime navigation, and when navigating near hazards or in narrow channels.
What should you do if the lookout reports a faint light ahead?
Use binoculars to confirm the light, check radar to assess its range and movement, calculate CPA/TCPA, and take action if necessary to avoid collision.
How does radar help in maintaining a proper lookout?
Radar detects distant objects, measures range and bearing, and can track targets using ARPA to determine CPA and TCPA for collision risk assessment.
What role does AIS play in maintaining a lookout?
AIS provides information about nearby vessels, such as name, position, speed, and course, which helps identify potential collision risks.
Can a proper lookout rely solely on radar and AIS? Why or why not?
No, because radar and AIS cannot detect uncharted hazards, small boats without reflectors, or floating debris. Human senses (sight and hearing) remain essential.
What action should you take if you hear a foghorn but cannot see the source?
Reduce speed, use your own fog signals, intensify radar monitoring, and prepare for potential evasive action while maintaining situational awareness.
What are the risks of not maintaining a proper lookout?
Increased risk of collisions, grounding, or hitting uncharted obstacles, especially in poor visibility or traffic-dense areas.
How do you cross-check visual observations with electronic tools during a watch?
Use binoculars for distant objects, verify with radar to calculate range and movement, and confirm vessel details or movements using AIS or ECDIS.
You detect a fishing boat visually but not on radar. What do you do?
Maintain visual monitoring, assess its course and speed relative to your vessel, reduce speed if necessary, and take early action to avoid collision.
During restricted visibility, how can Rule 5 be applied effectively?
Reduce speed, assign additional lookouts if needed, use fog signals, continuously monitor radar and ARPA, and maintain readiness to take evasive action.
You notice a small craft drifting with no AIS signal. How do you respond?
Alert the Master, monitor its position visually and with radar, and alter course or reduce speed to pass at a safe distance.
How does Rule 5 connect with Rule 6 (Safe Speed)?
A proper lookout helps assess the conditions and traffic density, allowing the OOW to determine and maintain a safe speed appropriate to the situation.