Question 911 Rules of the Road

The correct answer is C) It is only used to supplement short blasts of the whistle. This is the correct answer because according to the International Regulations for Preventing Collisions at Sea (COLREGS), the use of a light to supplement whistle signals is optional, and it is only used to supplement short blasts of the whistle, not for all whistle signals. The regulations do not require the use of such a light, nor does it specify that the light must have the same characteristics as a masthead light. The other options are incorrect because option A) is not accurate, option B) is incorrect as the use of the light is not required, and option D) is incorrect as none of the other options are true.