How must a vessel determine the risk of collision?

A vessel must determine the risk of collision by using all available means appropriate to the conditions because this comprehensive approach ensures a thorough assessment of the navigational environment. Factors such as visibility, traffic density, and the specific capabilities of the vessel, including its radar and lookout resources, all play crucial roles in understanding potential collisions.

Using only radar might not provide a complete picture, especially in scenarios with limited visibility or where radar may not detect smaller vessels or those close to the shore. Similarly, ignoring other vessels or assuming that all signals indicate safe passage undermines the principles of safe navigation and situational awareness. This holistic strategy aligns with the COLREGs, which emphasize the importance of vigilance and using all available resources to avoid collisions effectively.