Overtaking means you are positioned behind another vessel in a way that you would pass it on its stern. At night, the clear visual cue for this is seeing only the other vessel’s stern light, which shows you are behind it and plan to pass aft of it. That is why the statement describing seeing only the stern light of the vessel ahead and intending to pass astern correctly identifies overtaking. The other scenarios describe head-on or crossing situations (seeing both bow lights, or seeing a starboard light and crossing to the other side) and do not indicate overtaking.

When a vessel signals distress, your safety is tied to giving the other boat space to operate and to assist if you can. The proper action is to give way, slow down, and proceed with extreme caution, while paying close attention to the distress signals and following any instructions from the distressed vessel. This approach helps prevent collisions and allows you to render aid if you’re able to do so without creating additional danger. Maintaining course would increase the risk of collision or complicate the rescue, increasing danger to both vessels. Speeding up to push through the passage ignores the urgency of the situation and can worsen the distress. Ignoring the signals is not acceptable and violates the duty to assist others in distress.

Overtaking is identified by the direction from which the behind vessel approaches the ahead vessel. If the vessel behind is coming from more than 22.5 degrees abaft the ahead vessel’s beam, it is overtaking. At night, this geometry means the astern vessel will see only the ahead vessel’s stern light, since the forward side lights and bow light are oriented forward and out of view behind the other vessel. The cut-off angle of 22.5 degrees aft of midships is what makes the stern light the only navigation light visible to the overtaking vessel. So, seeing only the stern lights of the vessel ahead correctly describes an overtaking situation. The other options depict head-on or non-specific lighting scenarios that don’t define overtaking.

Day shapes communicate what a vessel is doing so other ships can take appropriate action. For diving or underwater operations, the specific signal is a vertical line of three shapes: a ball on top, a diamond in the middle, and a ball at the bottom. This Ball-Diamond-Ball pattern tells nearby vessels that divers are in the water and the operating vessel may be restricted in its ability to maneuver, so others should proceed with caution and keep a safe distance. The other options don’t convey diving operations. A single ball indicates something like a vessel at anchor, and a diamond alone or three balls in a line do not communicate the presence of divers in the water.