BOTH INTERNATIONAL & INLAND A single towing light will be carried above a vessel's stern light under which of the following situations?

Correct Answer: Option B — only if she is towing astern

Rule 24(a)(iv) requires a vessel towing astern to exhibit a yellow towing light in a vertical line above her white stern light. This configuration is unique to towing astern, helping overtaking vessels identify the presence of a towline behind the tug.