Necessity of Diligent Lookout and Timely Preventive Actions to Avoid Collision Risk

The Agency for Investigation of Accidents in Air, Marine, and Rail Transport emphasizes that diligent lookout and timely preventive actions are fundamental principles of safe and responsible navigation.
A proper lookout, which is the primary duty of a navigator, must be conducted continuously through visual observation, supplemented by all available technical means. Any action taken to avoid a collision must ensure that vessels pass each other at a safe distance, and the effectiveness of such action must be carefully and continuously monitored until the other vessel is safely clear.
A navigator’s responsibility is not just to avoid an imminent collision when danger becomes obvious (which would already be a delayed response), but rather to take all necessary measures to avoid even the risk of collision or dangerously close situations, acting early and at a sufficient distance. As stated in the COLREGs:
“If there is the slightest doubt, it must be assumed that a risk of collision exists.”
Preventive measures for a comprehensive assessment of navigational situations and collision risk, in accordance with COLREGs, include:
Diligent and continuous visual monitoring and listening
Use of all available technical means
Adjusting speed to prevailing conditions
Timely and effective actions to avoid collision.
Use of warning signals when in doubt about the adequacy of another vessel’s actions.

Recipients: This safety advisory is intended for: All individuals operating vessels and members of navigational watch, students and trainees preparing for these roles, legal entities providing maritime education and training, examination boards at the Ministry of Marine Affairs and Port Authorities related to navigation rules and collision avoidance.