The stern light on a vessel is typically white with a 135 degree cone of visibility. From the 1980 US Inland Rules only pilot vessels, vessels aground, vessels not under command or vessels with restricted maneuverability may show red astern. The combination and orientAtion of red and white all-around lights is dictated by category. A towing vessel shall have a yellow light above it's stern light whether towing behind or alongside. The 1972 International Rules do not provide for the yellow towing light astern when the towed vessel is alongside of the towing vessel. Lastly, a sailing vessel under 20 meters in length may at her option display an all-around red over green at her masthead. As a matter of common practice the author has never actually seen this.
A boat's stern light is white. It is located at the rear (stern) of the vessel and is used to indicate the boat's presence to other vessels. The white light must be visible from all directions, ensuring safety and visibility during nighttime navigation.
A stern light is a white navigation light on the rear (stern) of a watercraft. It helps other vessels determine the direction the boat is headed in low visibility conditions or at night. The white light indicates the boat's position and helps prevent collisions on the water.
You are approaching the stern of another vessel
In an emergency situation aboard a vessel, a red light at the stern typically signifies that the vessel is not under command and has limited ability to maneuver. This is a signal to other vessels to proceed with caution and give way to the vessel displaying the red light. It is important for other vessels to maintain a safe distance and be prepared to assist if needed.
Properly, it is a white light, and elevated higher than the red/green lights on the front of the boat.
yellow A common sight on many rivers and waterways are "tugs and tows". When a tug tows or pulls a barge they must display certain lights that identify what they are, and how they are proceeding. Knowing the difference is very important! A tug towing a barge at night might have several hundred feet of cable between the two vessels-cable that is impossible to see. If you don't know what the lights mean, you might think that they are two different vessels and attempt to pass between them at your peril. a tug less than 50 meters in length, with a length of tow under 200 meters. If the tug had the barge alongside, it would show two yellow stern lights, instead of a yellow over white stern light combination. ETA: Its more than just commercial vessels, that light applies to all vessels that have the ability to tow. Also its not just the color of the tow light, but also the rest of the lights that are required at night. Stern light, side lights, masthead lights (except above the Huey P. Long bridge.)
Blood vessels appear green or blue in color due to the way light interacts with the skin. This hue is not the actual color of the blood vessels, but rather a visual effect caused by the absorption and reflection of light. In reality, blood vessels are typically a reddish hue due to the presence of red blood cells.
Port (red) and Starboard (green) running lights and a white light which will be mounted on either the stern or the masthead.
Power-driven vessels less than 65.6 feet long must exhibit a white masthead light and a white stern light between sunset and sunrise when underway. Additionally, they should also display red and green sidelights when the visibility is restricted.
All power vessels must have a white Stern light. Rules differ slightly between power boats and sailing vessels, where sailing vessels can have both their port, starboard and stern lights on their mast. An all around white light denotes a vessel at anchor. If a vessel is longer then I think its 200', then they must have two all around white lights, one forward and one aft in addition to their red and green navigation lights. Vessels towing have a yellow light which signifies they are towing. They also have the back white light. The white light stands higher in the air its usually on a post or something so it could be higher in the air.
Sailboats are typically equipped with several key navigation lights to ensure safety and visibility at night or in low-light conditions. These include a white stern light at the back, red and green sidelights at the bow (port and starboard, respectively), and an all-round white light for anchored vessels. Additionally, larger sailboats may have masthead lights and signal lights for specific maneuvers. The arrangement and color of these lights help other vessels determine the sailboat's direction and status.
A masthead light, side lights and a stern light are the lights that power driven vessels less than 65.6 feet long and underway between sunset and sunrise exhibit.