Article by Capt. Steve Katz
Underwater Lights
Underwater lights have become a very popular accessory for boats of all sizes and while it is not a necessity, it sure looks good at the dock and may even help you catch fish.
Once reserved for large yachts, their low prices and great light output makes underwater lights affordable for boats of any size. Today, underwater lights are available in many styles and colors, allowing the boater to customize the color to coordinate with other lighting.
Will underwater lights help you catch fish? The consensus is yes! The light attracts bait, such as plankton and baitfish. The bait and light attract larger predators, especially those lurking in the shadows of the lights. Coming in several colors, blue lights penetrate the water further. Green seems to be popular by attracting fish and white has all the colors together. The debate of which color to use for your type of fishing will continue, so use whatever color works for you.
Manufactures are making the decision easier by making lights that have multiple colors built-in, where the color of the light in a single fixture can be changed by a quick flip of the light switch. Some lights can also flash or actually strobe, which is a neat feature that may also attract fish.
While most of today’s underwater lights use Light Emitting Diodes (LED), it wasn’t always that way. The first generation of lights were very expensive, costing over $1,000 and required a large, 2-inch or more, hole cut into the boat. They were not always bright, easily overheated and burned out quickly.
The most popular of this generation of light is the High Intensity Discharge (HID) style light. This light requires a thru-hull fixture permanently installed in the fiberglass and the light assembly could be removed from inside the boat for service or bulb replacement. Less expensive lights of this style used standard automotive headlight bulbs inside the fixture to provide more affordable illumination. If you wanted a certain color, a special colored lens was placed into the housing to display that color underwater. These first generation lights began the trend we see today with so many options for boaters.
Mounting styles – the modern underwater light are either a thru- hull or surface mount style, and powered by LED’s. A thru-hull mount is similar to the installation of a transducer. A large 2-inch hole is cut in the bottom of the boat and a metal fitting with a “window” is installed from the outside of the boat. This allows the light fixture to be nearly flush with the surface of the hull for a clean look.
Surface mount underwater lights have become very popular in recent years. This installation only requires a hole of ½” or so cut into the hull for the wiring. The light is attached to the surface of the hull (not recommended for running surfaces) and only protrudes about ¾” or so depending on the light. The fixture is often made of metal but some are plastic, attached to the hull with a few screws and proper sealant. With the surface mount style, the small hole in the boat is covered by the light and marine sealant.
Power and wiring – Most of today’s underwater lights can run from a 12 volt DC power source. Many of the same lights can also run from a 24 volt DC source too, such as the Seablaze3 or Amphibian LED lights. While most of the modern lights are powered directly to the fixture, there are some that require a driver, ballast or transformer, mounted near the lights. There are some underwater lights that are powered from an A/C power source and have a transformer or ballast, though this is not very popular anymore for the pleasure boat lights.
The LED lights do not use very much power and therefore do not require large wiring or heavy duty circuits. The popular Seablaze3 or Amphibian lights require less than 3 amps of 12 volt power each, which in comparison is less than half of the power for a typical Rule 1500 bilge pump. If you decide to line the transom of your boat with underwater lights, you will need to be sure you have the proper wiring to accommodate the load. Most boaters wire the lights so that they all turn on with the same switch. In this case, one new circuit can be run to the transom to power all the lights, using the proper wire and fuse size.
A few model of lights, such as the Seablaze models can have multiple colors of light inside one fixture. A unique engineering feature is that the light colors and function can be controlled using the standard two wire connection to a single switch. With this feature, each quick flip of the switch cycles through the color options of the light which is a simple way to control your lights without complicated controls.
How bright are the lights? – It seems that each manufacturer measures the brightness of their lights differently, making comparisons difficult. One of the best ways to select a light is to see it working on a boat at night. Walking through the marina at night is the best way to see the real world brightness of the light. Most boaters will be excited to talk about their lights.
There are a few new lights that are designed for the smallest of boats with a simple, fast installation. The “Liquid Lite” is a small LED light that is installed in place of the drain plug in the back of the boat; this allows the wire to be inside the boat too, not requiring any new holes in your boat. This is a fast and easy way to enjoy underwater lighting. There are also underwater LED lights designed to mount on to your existing trim tabs or even the lower unit of an outboard.
Check out the assortment of underwater lights on the market. They will help you catch fish and make your boat look cool sitting at the dock.
Captain Steve Katz is the owner of Steve's Marine Service and holds NMEA MEI, AMEI, NMEA2000 certificates, ABYC Master Technician certification and factory training from many manufacturers.