Question 3452 Deck General

The correct answer is B) Immediately. According to the International Regulations for Preventing Collisions at Sea (COLREGS), a vessel being towed must sound the appropriate fog signals immediately when entering a fog bank, regardless of the location of the towing vessel. This is to alert other vessels in the area of the presence of the towed vessel, which may not be easily visible in the fog. The other answer choices are incorrect because they do not align with this regulation - the fog signals should not be delayed until the rig enters the fog, when the towing vessel can no longer be seen, or when the towing vessel enters the fog.