How Far Does Light Travel Underwater

How Far Does Light Travel Underwater? A large bulk of today’s underwater lights for boats and docks fall short of people’s expectations. Some individuals complain the luminaries look bright, when tested above water, but appear dull when installed underwater.

Generally speaking, there’s probably nothing wrong with the lights. Instead, it is likely the person failed to take into account the density and absorption rate of water.

Dealing with Light Loss

According to scientists, water is roughly 800 times denser, compared to air. Because of this, light gets absorbed in water at a higher rate. This phenomenon contributes to dullness and decreased quality in illumination. Light is absorbed at different rates, as it hits the water. On the surface, a significant amount of sunlight is reflected from the water, which is why looking down at the surface of water can be unbearable during mid-afternoon conditions.

At roughly five meters, red starts to appear fuzzy. Next, at 10-20 meters, orange and yellow start to disappear. At depths of 50 meters, green and blue are only visible. Lastly, at 200 meters, blue disappears, leaving violet as the last remaining color. This is also where the sunlight zone (euphotic) ends and where the twilight zone (dysphotic) begins. There is not enough light in the dysphotic zone to stimulate photosynthesis in plants.

Four major factors that affect light absorption in water includes the following: weather, conditions at the surface, distance of the subject and depth.

In addition to absorption rates, refraction can be an issue for underwater lights. By comparison, air has a refraction index value of 1.0003, while water features a refractive index value of 1.33. This difference is the reason objects appear closer and larger (sometimes up to 25 percent!) underwater.

Solutions for Underwater Illumination

In order to ensure clarity when setting up underwater lights, they have to be very powerful – beyond the capabilities of above-ground luminaries. It might also help to use a more focused beam, such as a spotlight over a floodlight, if the underwater light is intended for long-distance viewing or support. In some cases, multiple beams or light sources might be required to achieve widespread beam configurations, especially in murky water or in bodies of water that experience a lot of waves and movement.

For underwater photographers, flash guns (also known as underwater strobes) are particularly effective in restoring light in images. For best results, underwater photographers may use dual strobes for increased quality and control over beam angles. Moreover, the strobe must be synced with the camera. Click here to purchase LED underwater lights.

Underwater Red LED Lights Can Improve Visibility In Submarines

Not all marine vessels rely on white lights for illumination. Some units, like underwater submarines, use other colors to maximize visibility. This practice can also be applied to covert military operations, as well as discreet patrollers monitoring docks and passageways at night. Why do submarines use Red LED lights?

Transitioning to Darkness

When a submarine is on the surface during the day, it uses normal LEDs or fluorescent tube-style white lights. These luminaries are typically marine grade, offering some form of protection from the ingress of water or corrosive agents (saltwater). Sub operators turn on red light when transitioning to complete darkness. A common configuration consists of mostly red light with very little white light.

Eventually, the control room will be completely engulfed in black. This is to ensure maximum visibility when looking through a periscope. Without a dark room, individuals would be temporary blind looking to a periscope, as their eyes adjust to the nighttime environment. Furthermore, there is a huge risk related to light leakage when using white lights in submarines, even when covers are utilized to prevent light from escaping the vessel.

Why Red LED Lights?

Red light, with a wavelength measurement of 650 nm, provides optimal low-level lighting conditions for marine applications. It is least intrusive on natural, human night vision – without goggles. As a result, less time is wasted on acclimation during nighttime operations. Additionally, human error is greatly reduced when operators are able to clearly see in dark conditions. From a cost perspective, it’s cheaper to install red lights in control rooms, compared to equipping every worker and operator with specially designed goggles. To maximize natural nighttime vision, some sub operators wear a black patch over the eye they use to peek through a periscope.

This practice can also be observed in aviation control towers, movie theaters, observatories and planetariums. Another sector that uses red light is hunting. Like submarines, using red light when tracking or hunting nocturnal animals helps reduce spooking creatures on the field.
This article was provided by LarsonElectronics.com.

Selecting Underwater LED Lights For Boats

The type of underwater LED lights you install on your boat can greatly affect your experience in the water. With LEDs offering maximum flexibility in designs and configurations, individuals have numerous options for lighting up their vessel.

Read on to learn about different factors to take into consideration when choosing and installing underwater LED lights on your watercraft.

Flood vs Spot

Beam angles determine the density of the light beam, as it looks around the hull of the boat. If you’re relying on lights for guidance or for monitoring underwater operations, the beam configuration of the LED luminary will also affect the distance and spread of the light. With this in mind, a flood beam, measuring between 20 degrees to 120 degrees, is designed for wide-area applications. The distance of the beam is limited, trading off for its wide spread.

On the other hand, spot light beam configurations offer tight, intense illumination with a maximum measurement of 19 degrees. At such angles, boat operators are able to illuminate specific targets from far distances.

Colors and Color Temperatures

In addition to beam types, LEDs allow for unique color and color temperature configurations. White is the most common choice, which is ideal for shallow water with thick sand accumulation at the floor. Green is suitable for inland locations, while blue goes with just about any type of marine setting. Going beyond aesthetics, some boats require specific colors for underwater LED lights, depending on the activity being conducted. For instance, submersible lights that emit green beams are used to attract large fish.

When it comes to white light, individuals have several options for color temperatures. Choosing the right range can help improve visibility, as well as mood and aesthetics. Low color temperature settings, between 1,500K and 3,500K, features a yellowish color and does not penetrate the water well. On the high end of the spectrum, between 6,000K and 8,500K, light beams appear bluish and are perfect for deep water illumination.

Please visit Larson Electronics for more information regarding underwater lighting for boats.

Understanding IP and NEMA Ratings for LED Boat Lights

For sustained illumination in marine environments, which in most cases are rough, humid and watery, LED boat lights are reinforced with specific standards, such as Ingress Protection (IP) and National Electrical Manufacturers Association (NEMA) ratings.

IP and NEMA standards are the most common set of guidelines that allow operators to effectively gauge how far they can push lighting systems before succumbing to malfunction or failure. This article explains how to distinguish IP and NEMA ratings on LED boat lights.

IP Guidelines

IP ratings follow a standard format of ‘IP’ followed by two digits or letters. The first letter is related to the unit’s level of protection against solid particles. This indicator ranges from zero to six, with zero offering no special protection against solid objects. At the highest level, a starting digit of six provides dust tight protection or complete protection from dust. The second digit reveals the object’s level of protection against liquids. This salient indicator ranges from zero to 9K, which provides protection from hot jets (80 °C water) – associated with wash or spray down sessions.

IP ratings can also include additional letters for protection against specific hazards and conditions. A letter ‘F’ signifies oil resistance, a letter ‘H’ relates to high voltage and a letter ‘W’ offers protection from various weather-related conditions.

For LED boat lights, the most common IP ratings include IP67, IP56 and IP54.

NEMA Ratings

NEMA ratings are prevalent in the US and Canada, while IP guidelines are applicable worldwide. Moreover, the guidelines go beyond protection from liquids and dust. The rating system adds protection against corrosion resistance and hazardous atmospheres, related to flammable or explosive substances. NEMA enforces their ratings using a scale that ranges from one to 13. NEMA 1 is applicable to indoor enclosures with limited or general protection from dust (note: not dust tight), light, water and normal weather conditions.

NEMA 6 and NEMA 6P (as well as NEMA 4 and NEMA 4X) are most suitable for LED boat lights. This NEMA type provides protection in submersible conditions, with NEMA 6P offering extended periods of submersion in water or oil. This level of protection may also apply to manholes and quarries.

NEMA 7 to NEMA 10 are reserved for certain classifications of explosion proof protection. NEMA 10 adheres to compliance with MSHA guidelines for mining equipment. The last three NEMA ratings (NEMA 11, NEMA 12/12K and NEMA 13) are related to corrosion resistance and special elements.

IP and NEMA ratings are two different rating systems; however, some classifications intertwine with each other. For example, NEMA 1 is equivalent to IP10, while NEMA 6 and NEMA 6P corresponds to IP67.

For more information regarding boat lights, please visit – Larson Electronics.

 

 

 

 

 

Benefits of Corrosion Resistant Lights

LED boat lights are exposed to a wide range of harsh elements in the water, such as small rocks, dirt and salt (depending on the body of water). Because of this, waterproof protection is not enough to keep your lights running in optimal condition at sea.

For complete protection, you need corrosion resistant lights that are capable of preventing damage caused by saltwater.

Waterproof vs Corrosion Resistant Lights

Waterproof ratings, such as IP65 and IP67, are useful for preventing water from entering the unit. But water isn’t all that boat lights can succumb to in the ocean. Rough treatment and constant abrasion from corrosive agents, such as salt and solvents used for cleaning or wash-down sessions, could easily destroy luminaries. Without proper protection, salt and UV light can cause housings to warp. This is common in boat lights that use flimsy plastic.

When you’re out in the ocean, reliability matters. This is what corrosion resistant LED boat lights can offer. The units are capable of decreasing chances of premature failure by ensuring all of the components are working properly. From a cost perspective, investing in corrosion resistant units may help reduce maintenance and replacement costs associated with marine lighting systems.

Lights with saltwater damage appear worn out, as the lens often take on an abrasive film. This type of damage can reduce the luminary’s illuminative features, forcing operators to either replace the light or use more units to light up the boat. Using more lights will result in higher energy consumption rates, which should be avoided at all costs on boats, since power sources are limited to batteries and compact generators.

What Makes LED Boat Lights Corrosion Resistant?

Corrosion resistant lights for marine applications are manufactured differently, compared to mainstream, low-quality units. The lights consist of materials that can withstand saltwater corrosion, such as glass and high-strength stainless steel. Focusing on the latter component, manufacturers typically treat the metal with robust coatings and paint in order to make the surface more resilient.

Glass is a suitable material for the lens cover. Most standard boat lights for consumers are enclosed in transparent glass. Lights on docks and marine locations with limited activity may use corrosion resistant lights with glass lenses. For such lighting systems, manufacturers may choose to apply thick glass to prevent breaking when exposed to rough conditions. Other materials that are used to enforce corrosion resistance includes rubber. This material is used around wiring hubs and other openings to prevent saltwater from entering the unit. For more information visit: http://www.larsonelectronics.com/c-277-led-boat-lights.aspx