We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is a Deck Prism?

K.C. Bruning
By
Updated May 23, 2024
Our promise to you
WikiMotors is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WikiMotors, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A deck prism, also known as a dead light or deck light, is a piece of molded glass that reflects light into the lower reaches of a ship. It was used on wooden ships before the availability of electricity as a safer alternative for lighting than kerosene and oil lamps or candles. The prisms have a flat base, which rises to a smaller pointed or rounded top. They were typically hung from the ceiling, under a small hole on deck, with the pointed side hanging down so that light could come in from above. Deck prisms have several sides so that light that comes through the base can reflect on multiple surfaces below deck.

Though the earliest versions of deck prism have been traced back to the 1840s, it is believed they were used many years — and possibly centuries — previous to that date. Original deck prisms are rare and difficult to find, though there are some that can be viewed in nautical museum collections. It can also be challenging to determine their age, as glass is not easily dated. There has also been no solid information as to how deck prisms were developed or who, if anyone in particular, was responsible for their invention.

All deck prisms have multiple sides in order to allow for the even distribution of light below deck. Otherwise, they can come in a variety of shapes and sizes. A typical deck prism will have a circular base with a domed or pointed top. Some have a rectangular base that rises up to a three-dimensional triangle.

From the top side of the deck, the prism will appear as a flat piece of round or rectangular glass. Under the deck, it has a look similar to a light fixture. It can be secured into the deck or hang from a holder. There can be one or multiple deck prisms on a ship, usually depending upon the size of the craft.

The deck prism continues to be used in some sailing ships, but primarily as a nostalgic decorative element. Though they are not meant to replace electricity, the prisms can still help to light the areas below deck and potentially save on energy costs. Reproductions of traditional deck prisms are also sold as decorative items for nautical enthusiasts. They are usually either mounted so that they can hang from a special holder, or sit flat side down on a pedestal. The prisms are also marketed in a variety of colors and even incorporated into novelty items such as Christmas ornaments.

WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
K.C. Bruning
By K.C. Bruning , Former Writer
Kendahl Cruver Bruning, a versatile writer and editor, creates engaging content for a wide range of publications and platforms, including WikiMotors. With a degree in English, she crafts compelling blog posts, web copy, resumes, and articles that resonate with readers. Bruning also showcases her passion for writing and learning through her own review site and podcast, offering unique perspectives on various topics.

Discussion Comments

K.C. Bruning

K.C. Bruning

Former Writer

Kendahl Cruver Bruning, a versatile writer and editor, creates engaging content for a wide range of publications and...
Learn more
WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.