INTERNATIONAL ONLY If a towing vessel and her tow are severely restricted in their ability to deviate from their course, the towing vessel shall show lights in addition to her towing identification lights. When shall these additional lights be shown?

Correct Answer: Option B — If the vessel is towed astern

Rule 24(h) specifies that a vessel engaged in towing, when severely restricted in her ability to deviate from her course, must display the lights prescribed in Rule 27(b) for a vessel restricted in her ability to maneuver, but only when the vessel is being towed astern.