COLREGs Scenarios Practice Test

In poor visibility, vessels must exercise extra caution and be prepared to take early action to avoid collision. The rule that directly covers conduct in such circumstances is the rule dealing with conduct of vessels in or near a narrow channel, or in doubt about another vessel’s actions. It requires proceeding with caution at a safe speed and being ready to take action to avoid collision, using all available means to determine risk. In a head-on encounter with limited visibility, this rule tells you to stay vigilant, adjust speed as needed, and be prepared to alter course if necessary, while still following the general requirements to maintain a proper look-out and to avoid collision. The other rules—look-out, safe speed, and action to avoid collision—support these actions but do not specifically prescribe the conduct for this scenario, making this rule the best fit.