A Brief History of Ship Navigation Lights

Pre- 16th Century

Ever since ancient times, seamen needed to find a way to signal their presence at night. Not only to light their way ahead but as well to prevent a collision with other ships.

They did so by installing lanterns on the bows of their ships. Since there were no regulations, it was all a matter of common sense.

One of the earliest ship light documentation dates back to the first century. The greek writer 'Pluarquede' mentioned that lanterns were used on ships, as quoted: "lanternoe militares." Later in AD 107-112, a cylindrical lantern is seen on the stern of a warship.

Much later, "Phanal" appeared first in a text by Rabelais in 1552, denoting "a fire enclosed in a protective compartment" placed at the highest point of the stern of a ship to be visible at night.

The 17th and 18th Century

In the 17th century, to be recognized at sea, the French admiral's ships bore three large stern lanterns at the stern. This was similar to the general's galleys.

The squadron commanders had just one stern lantern available. They were heavy hexagonal glazed lanterns that stood on an iron stand. This was along with smaller lamps commonly seen hanging at the top of the masts.

french ship with lanterns on stern

At the same time, many other lanterns were placed to illuminate the ship's compartments, such as the ship's hold and the compasses.  From 1820 onwards, regulations came into play, mainly due to the rise of steamships which were much faster.

The first known regulation for navigation lights that ships had to comply with dates from 1838. The United States passed an act that required steamboats, running between sunset and sunrise, to carry one or more signal lights. Although the color, location, and the matter of visibility were not specified.

The United Kingdom followed suit in 1846. In 1848, the admiralty of England specified that steam vessels had to display red and green sidelights, a white masthead light while underway, and single white light at anchor. The U.S. Congress then extended the light requirements to sailing vessels in 1849.

Click on the link below to read the complete news item published in the London Gazette on the 11th of July, 1848

In collaboration with the French government, the British Board developed a new set of regulations in 1863. More than thirty maritime countries, including Germany and the United States, followed suit. In 1864, President Abraham Lincoln signed the 'Rules to Prevent Collisions at Sea', making it part of U.S. law.

In 1889 the United States convened the first International Maritime Conference to consider regulations for preventing collisions. This resulted in the 'Washington Conference Rules' in 1890 which became internationally effective in 1897. One of these rules required steamships to carry a second masthead light. 

In 1914, after the infamous Titanic disaster, the International Convention for the Safety of Life at Sea (SOLAS) was formed. 

19th Century and Now

The international 1948 Safety of Life at Sea Conference recommended a mandatory second masthead light solely for power-driven vessels over 150 feet long and a fixed stern light for almost all ships. Collision Regulations would effect both Recreational and commercial boaters to assist in safe passage. 

Ever since, the regulations have changed little. 

These harmonized rules recognized worldwide were first introduced by the International Maritime Organization in 1972 for ratification by member states. Beginning July 15, 1977, the International Rules for Preventing Collisions at Sea (IRPCS), more commonly known as COLREGs, became the rule of law.

Nowadays, it is is still the foundational navigational document for all vessels operating on the high seas.

Fresnel lenses

oil light fresnell lenses

Augustin Jean Fresnel (1788-1827) was a French engineer and physicist. He significantly contributed to optics by studying the behavior of light both theoretically and experimentally. Augustin continued Thomas Young's experiment on diffraction and eventually confirmed the wave theory of light. Together with François Arago, he investigated polarized light.

Augustin invented the lenses that are still used in navigation lights of today. Its primary advantage over conventional lenses is a reduction in material, which in the case of the strongly convex glass version, leads to a considerable weight saving. Due to the smaller thickness, the optical attenuation due to absorption is also more negligible. Eventually, the United States made usage of Fresnel lenses mandatory for navigation lights in 1910.

For more information about the glasses commonly used in ship lights,

please visit the page 'Glass for ship lights' below.

Starboard green and Port red lights

pair of port and starboard ship lights from Pascall Atkey & Son Cowes

In the first half of the 19th century, manufacturers mixed the colors of Starboard and Port. In 1847 the British Admiralty decreed that the Starboard would be the color green while port being the color red, which several other European countries adopted in 1858. Finally, in 1889, it was recorded in the international maritime regulations.

As of today, there are various theories why they chose green for Starboard and red for Port. However, the one that deemed me as the most logical is as follows. Starboard was on the steering wheel's side, so every helmsperson at sea knew that the helmsman would likely see you if you approached the ship from this side. Making this the "safe" side, thus green. The helmsman had less visibility on the port side; navigating to a boat from this side was hence much more dangerous, thus the color red.

A more romantic approach is that left is the place of the heart, explaining Port's color: red.

I could provide you this article partly thanks to the following sources:





Bernard Mahot - Les lanternes, phares et fanaux