Using Underwater Lights

New gear opens up the science of fishing lights

November 9, 2011
underwater lights on sport-fishing boat
Quality fishing lights do four distinct things: draw, illuminate, entertain and produce. David McCleaf

Ever-changing technology in the lighting field has resulted in a new generation of fish-attracting lights in both portable and in-hull versions.

Quality fishing lights do four distinct things: draw, illuminate, entertain and produce. With the first, the brightness permeating dark waters acts as visual chum. That is, the lights attract the food chain, from baitfish on up to predators, luring them with forage species and brightness. Lights also illuminate a large area, if not the entire space, around a boat. This provides a focal point, a shadow line (where the brightness fades to darkness — a prime ambush point for game fish), for anglers not only to fish or place baits along but also to monitor so they can find and quickly react to any large fish entering the lighted zone. The lights entertain because just about everything from baitfish to squid to juvenile game fish are likely to swim through the illuminated area. While waiting on the target fish, impatient anglers can keep busy jigging squid or baitfish or dip-netting tiny pelagics for quick study. And fishing lights help put more fish in the boat. Naturally, a good angler helps tremendously.

Fishing lights once again proved their worth during a recent overnighter in the Wilmington Canyon off Avalon, New Jersey, for mako sharks. In this instance, a portable green Hydro Glow light lured in squid, which we jigged up for live bait and used to tease the sharks into striking. And the illuminated swath of water made it easy for us to see and react to the sharks, which made baiting them easier. In addition to the makos, several blue sharks kept everyone on their toes beyond the midnight hour.


For in-hull fishing lights, LED technology now provides low-amperage and ultra-durable products that can withstand the pounding and abuse of rough seas. Unlike halogen and xenon/HID bulbs, LED lights do not throw off excessive heat and will not be damaged if accidentally left on when the boat is removed from the water. Surface-mount in-hull lights are becoming more in vogue compared to through-hull units, which require drilling a large hole in the vessel below the waterline to install fittings. By comparison, most surface-mount lights are affixed to the hull with screws and require just a single wire run through the hull.

Listed are just three providers of cutting-edge fishing lights. These companies — one with a popular portable unit and two with in-hull systems — are utilizing LED technology to achieve a brighter and larger “throw” of light with minimum battery drain. Here’s a peek at what they have to offer.

underwater lights on sport-fishing boat
Underwater LED lights act as visual chum, attracting all manner of curious sea life. Courtesy Lumishore

Long considered the leader in portable saltwater fishing lights, Hydro Glow (877-895-4569; made its name 13 years ago with a 4-foot fluorescent-green tube light complete with terminals that attach to a battery. Company president and angler Darrell Keith says the product was born out of necessity for a light that would not only stay underwater (instead of float) but also be efficient enough to operate all night without draining its battery. Hydro Glows meet both objectives and are precision-balanced so they submerge in an upright position to broadcast 360 degrees of light around a boat. Constructed for the rigors of a saltwater environment, their bulbs have a 20,000-hour life expectancy. These lights are used widely for not only swordfish, tuna and sharks but also inshore for fluke, flounder, redfish, seatrout, snook and tarpon, as well as baitfish. They retail for around $200.


In the LED category, Hydro Glow has 1-foot-long and 2-foot-long models with 162 LEDs and 324 LEDs, respectively. These featherweight lights have an 80,000-hour life expectancy. Like their predecessors, they are submersible and have weathered pressure changes down to 50 feet. They’re available in blue or green and sell for $95 and $169.99.

Due out this December is a 4-foot LED model designed exclusively for swordfish and tuna. It will contain over 600 lights and be the brightest and most durable portable light on the market, says Keith. The unit is an inch in diameter, with strips of LED lights mounted on three sides of the light for a full 360-degree throw. It’s touted as drawing only 2 amps and will come in green or blue violet. Expect it to sell for around $239.

A leading provider of innovative, bright high-quality LED marine lights for yachts and pleasure and fishing vessels, Lumishore (941-405-3302; now offers a line of surface-mount fishing lights in white, blue and green. Models SM20 (830 lumens), SM50 (1,210 lumens) and SM100 (2,310 lumens) have power comparable to a 50-, 75- and 150-watt xenon light, respectively, and a 50,000-hour life expectancy. At 12 volts, they’ll draw 1 amp, 1.5 amps and 3 amps, respectively, whereas at 24 volts they’ll draw half an amp, three-quarters amp and 1.5 amps.


Introduced this November, surface-mount model SM150-CCP (for Color Change Plus), which draws 5 amps at 12 volts and 2.5 amps at 24 volts and has power equivalent to a 150-watt xenon light, offers a range of colors: blue, white, cyan, green, magenta and red. It features three strobe speeds (as short as 30 seconds and as long as a couple of minutes) for any chosen color and three selectable output intensities in preset colors.

“The system is purchased as a set of two lights and a controller,” says Lumishore’s Keith Wansley. “The controller allows you to scroll through six standard colors, as well as activate the strobing. So if you wish, you can illuminate the water in six rotating colors or the ones of your choosing. Should more lights be desired, the original controller can handle up to 14 lights. We anticipate the new SM150-CCP to retail for around $3,000.”

Some of the hottest surface-mount fishing lights on the market are made by Shadow-Caster (727-474-2877; These high-intensity LED underwater lights are manufactured with 316 stainless-steel and polycarbonate housings and have a life expectancy of 40,000 hours. The three models, the SCM-4 (17-watt), SCM-6 (24-watt) and SCM-10V2 (42-watt), are available with a wireless controller with key fob to control dimming and strobing. The lights are priced at $479, $549 and $679, respectively.

underwater lights on sport-fishing boats
Underwater LED lights act as visual chum, attracting all manner of curious sea life. Courtesy Hydro Glow

What I’ve found as helpful as the lights’ performance is their relatively diminutive size, which provides a lot of latitude with where to mount them. For example, I have four pairs of model SCM-10V2 neatly arranged on the transom of my Mako 284, shooting outward for a bright and powerful throw. This model measures 10 inches in width, 214 inches in height and half an inch in thickness. The company’s smallest model, the SCM-4, measures 534 inches wide, 234 inches high and a half-inch thick. Given their sharp-looking 316 stainless-steel frames, the units appear more like a standard feature of the boat — right from the factory — rather than an aftermarket option. With most boats sporting aluminum towers, rails or trim, they blend right in.

These lights were developed by Brian Rogers, an electrical and optical engineer, and Jeff Pound, a military-electronics design engineer, hence their toughness in a salt environment and when coupled with trailer boats.

The Shadow-Casters come in great white, aqua green, Bimini blue, ultra blue and cool red. Current draw is 1.4 amps at 12 volts, and the lights generate over 2,000 lumens. For mounting, they require just two screws and a small hole for the submersible-grade cable. The units have internal thermal-throttling circuitry, which keeps them from getting too hot should they be left on when the boat is out of the water. Additionally, they include robust internal transient-surge protection, which protects the microprocessor-controlled switching power supply from dirty marine electrical systems.

Brand-new this November is the Color Caster model, which includes 10 LEDs, with each LED capable of changing to one of four colors. The light is controlled by one switch, quickly cycling power to rotate the color. One mode fades the lights through all four colors, whereas another mode fades between just blue and white (the company’s two most popular). Best yet, these new lights fit in the same footprint as the current ones for easy upgrades. Pricing had yet to be set at press time.

Bouncer’s Three Most Important Tips When Using Fishing Lights

1. When fishing a portable light in water to 40 or 50 feet deep, attach a float to the light to keep it near the surface. Also set it a few feet away from the boat to keep the light from rocking with the boat, which could diminish its uniform throw of light.

2. Fish the edges of the light, where it reaches toward the bottom, and also the perimeters of the lighted area.

3. Attach one or two Strip-Teaser strands on a short tether to the power cord close to a portable fishing light, which will mimic baitfish flashing near the light. This will attract more baitfish and, in turn, game fish.

To Strobe or Not to Strobe?

Strobing, incidentally, is becoming more popular with fishing lights, as the pulsing and flashing has proven advantageous in attracting fish. Could it be that the illusion is perceived as the reflection of baitfish, or is it simply that constant flashing catches the attention of fish? Either way, it works.

Strobing can involve a quick, repetitive cycle, which could be perceived by game fish as frantic baitfish, or a more spaced-out cycle, which predator fish could perceive as calm schooling fish unaware of its presence. Then add in the various colors to strobe with, and you get an idea just how fine-tuned an illusion you can create.

Expect to see this feature become even more commonplace in the near future.

baits attracted to underwater lights
Baits, like these squid, are naturally drawn to submerged lights and, in turn, attract predators. Courtesy Hydro Glow

Color Versus Color; Portable Versus In-Hull

The most productive fishing-light color remains a matter of opinion, although blue has become very popular of late. Capt. Bouncer Smith has spent a ton of nights swordfishing and baitfishing in the waters off South Florida and, as always, has his opinion. “We’ve been fishing the green Hydro Glow light for a long, long time and catching a lot of fish with it,” says Smith. “I later changed to a blue one because fish can see the blue from a greater distance than the green. Well, we caught a lot of fish with the blue light, but I can’t say it was drastically different over what we caught using the green light. But what I did notice is that the green light drew things closer to it, and with the blue light we rarely saw things close to the boat. They seemed to stay farther back. So green is better for bringing fish closer to the boat, in my opinion.”

As far as portable fish lights versus in-hull lights, that’s largely an issue of what you’re fishing for and where, how often you fish in darkness, how cool you want your boat to look and, of course, budget. Smith reports that with his Hydro Glow, he sees all the way around his boat, from transom to bow. He is currently using blue lights affixed to the underside of his engine bracket and aimed straight down. “These transom lights are more limited in the area they service and don’t illuminate the water like the Hydro Glow does,” says Smith.

Based on Smith’s findings, it stands to reason that gaining a strong broadcast from in-hull lights boils down to the number of lights you can afford to install and the position of these lights. Some of the best-arranged in-hull fish lights shoot not only directly out from the transom but also downward from underneath the hull. However, some ultra-bright LED hull lights shooting directly out from the back of the transom with multiple units cover both distance and depth.


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