In the vast ocean, ships are like stars in the night sky, twinkling with unique lights. These lights are not mere decorations but an important "language" for ships to communicate with the outside world—navigation lights. The turning on and off of navigation lights carry rich information, concerning the safety and order of ship navigation.

When Navigation Lights Turn On

The turning on of navigation lights is strictly regulated by time. From sunset to sunrise is the basic period for displaying navigation lights, and all ships under way must comply to ensure they can be detected in time during night navigation and avoid collisions. In the daytime with poor visibility, such as in heavy fog or torrential rain, ships also need to turn on navigation lights. At such times, natural light is obscured, and the illumination of navigation lights can significantly enhance the visibility of the ship, allowing other vessels to detect its presence in advance. During the nautical twilight, that is, the period before sunrise and after sunset when natural light gradually dims or brightens, ships also need to display navigation lights to compensate for the visual obstacles caused by insufficient light. In addition, the captain has the authority to decide to turn on navigation lights when deemed necessary, such as when navigating near areas with poor visibility or in regions with dark low clouds, to cope with sudden navigation situations.

Types and Meanings of Navigation Lights

Masthead Light: The Beacon Guiding Direction

The masthead light is installed above the centerline of the ship's bow and stern. Ships with a length of 50 meters or more should display both forward and aft masthead lights; ships with a length of less than 50 meters only need to display the aft masthead light. The white light emitted by the masthead light is like the eyes of a ship under way, indicating the direction of travel. It allows other ships to clearly know the bow direction of the ship, thereby accurately judging the meeting situation and making advance preparations for avoidance.

Side Lights: The Signal Distinguishing Left and Right

The red light on the ship's port side and the green light on the starboard side constitute the side lights. When the ship is moving through the water, the side lights turn on, and their function is to indicate the port and starboard sides of the ship. This simple distinction of red and green is crucial for maritime traffic. If another ship can only see the red light of a certain ship, it means that the ship is on the port side of that ship; if it can only see the green light, it is on the starboard side; if both red and green lights can be seen at the same time, it is directly ahead. Through side lights, ships can quickly judge their relative positions and effectively avoid collisions.

Stern Light: The Marker for the Ship's Stern

The stern light is installed as close to the stern of the ship as possible and emits white light. When the ship is moving through the water, the stern light turns on, and it is used to display the ship's motion and identify the motion of other ships. It not only provides a clear stern marker for the ship itself but also helps other ships judge the direction and speed changes of the ship's movement, providing important security for safe navigation at sea.

Towing Light: The Yellow Light Warning of Towing

The towing light has the same characteristics as the stern light but emits yellow light. When a ship is engaged in towing operations, the towing light turns on, and its function is to send a warning signal to surrounding ships, indicating that the ship is carrying out towing operations. This special light signal reminds other ships to pay special attention and give way, avoiding potential dangers caused by towing operations and ensuring the safe progress of towing.

All-round Light: The Signal Light for Special Situations

The all-round light is a navigation light that displays uninterrupted light within a 360-degree horizontal arc. Different colors of all-round lights have different meanings. For example, a ship out of control should display two all-round red lights at night, indicating that the ship is in an uncontrollable state and requires special attention and avoidance from other ships. An anchored ship should display an all-round white light (anchor light) at the bow and stern at night, informing surrounding ships that the ship is in an anchored state and will not move, reminding passing ships to maintain a safe distance.

As an important signaling system for marine navigation signal light, the correct use of navigation lights is crucial for maintaining maritime traffic order and ensuring the safety of ship navigation. Every crew member should be proficient in the rules and meanings of navigation lights to ensure that in the vast ocean, they can accurately communicate with the outside world through these twinkling lights and safely reach their destination.