A marine lantern is a type of lighting device specially designed for use in marine environments, mainly on ships and boats. These lamps are vital for navigation, safety and signalling. Some of their key features are as follows:

1. Durability: Marine lights are built to withstand harsh marine conditions, including exposure to seawater, humidity and bad weather. They are often made of corrosion-resistant materials such as brass or stainless steel.

2. Visibility: Many marine lamps are designed to emit light that is visible from long distances, making them essential for night navigation or in conditions of poor visibility.

3. Color Coding: Marine lights often have colored lenses or filters (red, green, white or yellow) to indicate different functions.

This specific lamp is manufactured by the company Hughes & Co. Hughes and Son were originally clock makers in the East End of London, who later supplied ships coming to the Thames with sextants and chronometers. This specific mast-head light was intended for use in relatively small boats, where the installation of three separate lights required relatively high cost of installing and operating.

In 1838 for the first time the United States of America passed a law requiring that steamships traveling between sunset and sunrise to carry one or more signaling lights without yet specifying the color, visibility and positions on board where the lights would be placed.

In 1846 the United Kingdom passed legislation and regulations requiring all steamships to carry navigation lights. English Admiralty from 1848 required steamships to display red and green side lights.

This specific triple light was manufactured between 1838 and 1846, and clearly shows that even before institutionalization a customary rule had been created regarding the colors of the navigation lights.