When are vessels permitted to depart from the requirements of the Rules?

• A. Never
• B. When necessary to avoid immediate danger
• C. When signaling with whistle
• D. When necessary to avoid immediate danger but only in clear weather

Answer: (B)

The main idea is that the collision-prevention rules are binding, but safety comes first. You may depart from the Rules only to the extent needed to avoid imminent danger to lives at sea, the vessel, or its cargo. Once the danger is past, you should return to full compliance and, if possible, inform others of your actions.

This is why the correct answer is that departure is permitted when necessary to avoid immediate danger. Following the Rules is not a license to create risk; if sticking to a rule would cause a collision or other serious danger, taking the prudent action to avert that danger is allowed.

Why the other ideas don’t fit: rules aren’t suspended for signaling or weather conditions; whistle signals are part of how you comply with the Rules, not a general exemption. And departing only in clear weather would inappropriately limit the safety provision—the allowance to deviate applies to avoiding imminent danger regardless of weather, since danger is what matters. Never departing is incorrect because safety can require temporary deviation.