USCG Rules of the Road Questions and Answers

Rule 24(a) mandates that a power-driven vessel towing astern must display two masthead lights in a vertical line. If the length of the tow exceeds 200 meters, three masthead lights are required. The presence of these vertical masthead lights, combined with sidelights and a stern light, identifies a vessel engaged in towing.

Under Inland Navigation Rules, for the condition where 'What is the minimum vessel length which must show two white masthead lights, one forward and one aft, when underway at night', the correct requirement is: '50 meters'. This standard ensures clear navigational intent and collision avoidance.

Rule 34(d) (Inland) and Rule 34(d) (International) require a vessel being overtaken to sound the danger signal—five or more short, rapid blasts—if she fails to understand the intentions of the overtaking vessel or is in doubt whether sufficient action is being taken by the overtaking vessel to avoid collision.

Under Inland Navigation Rules, for the condition where 'Which vessel would have no white lights visible when meeting her head-on', the correct requirement is: 'A vessel not under command'. This standard ensures clear navigational intent and collision avoidance.

Rule 1(d) allows for special rules made by the government for ships of war. Under 33 CFR 83.01(d), U.S. Navy submarines are authorized to display an intermittent flashing amber (yellow) beacon for identification purposes when operating on the surface, as this light is not otherwise used for standard navigation lights.

Rule 1(c) permits special station or signal lights for warships. Under these provisions, the Secretary of the Navy has authorized an intermittent flashing amber (yellow) beacon as an additional navigational light to identify submarines operating on the surface, enhancing safety due to their low profile.