From the August 2005 issue of Scuba Diving magazine
By Bill Kendig
Photography by Joseph Byrd

Dive Lights Reviewed in This Article

If you're in the market for a dive light, you'll notice a new breed in your dive store's display case. Next to the beams with traditional halogen and xenon bulbs, you'll now find primary dive lights incorporating LED and HID bulbs.

It's all part of a shift in light technology that some manufacturers say will make the traditional incandescent dive light a thing of the past. Why? Because while LED and HID bulbs have different advantages and disadvantages (see: "The ABCs of HID and LED," p. 106), they can both be used to make bright dive lights that use less energy, require fewer (or no) bulb changes and that hold up to abuse better than traditional dive lights.

We invited all manufacturers of dive lights to submit their best examples of these technologies, and received 19 shining examples that fall into three categories: primary dive lights, backup lights and tank markers.

Putting Them to the Test

First we assembled the lights, went through all the manuals and charted the basics: prices, burn times, batteries, bulbs, switches and accessories (see chart, p. 106). Because of the many differences among lights (bulbs, lens/reflectors, batteries and degree of beam) and differing claims of brightness (watts, candle power, lumens and color temperature), we decided to compare them based on illuminance, a measure of how much light falls on a surface at a specific distance from the light source.

In our darkened shop, we placed each light six feet away from a white screen. Using a Sekonic L-308S digital light meter, we took readings at the center of the "hot spot" and at 12 inches from the center. This gave us a consistent, real-world measurement of how the rubber meets the road, or, in this case, where the light meets the lobster. By sampling the hot spot and the periphery, we were also able to measure how wide or focused the beam was. Our chart lists these readings in exposure value (EV) units. A tightly focused beam will have a high EV reading at the center, but drops off dramatically as you move out from the center. Wider beams have less precipitous drop-offs.

With the measurements done, we took the beams into the water to tan some fish and get a sense of how they perform in everyday use. The following reviews and product ratings are based on the data collected from lab, pool and ocean tests. The quality and brilliance of all these new lights was impressive and made rating these lights difficult. For this review, Testers' Choice lights were selected by a consensus of Scuba Lab staff based on a combination of long burn time, wide beam size and overall brightness.

Primary Lights - Testers' Choices

UNDERWATER KINETICS Light Cannon 100

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| UNDERWATER KINETICS Light Cannon 100|
One of the first and still one of the best handheld HID lights, the Light Cannon 100 fired shots over the bows of all the other lights with the highest hot spot measurement of 10.8 EV. Under water, the blue-white beam is large and balanced, casting no shadows, but the tightly focused spot of light drops off to 4.5 EV a foot out from center. Powered by eight C-cell alkaline batteries, the light has a long burn time of three to four hours. An optional rechargeable battery kit is available from UK, and the light will accept NiMH rechargeable batteries. The Light Cannon comes with a locking switch that is easy to secure and operate with one hand and a pistol-grip handle, which can be replaced with an optional lantern-style handle. With intensity to spare, a long burn time and a reasonable price of $285.60 (the lowest of the HID lights we tested), the Light Cannon 100 is both a Testers' Choice and a Best Buy.

PRINCETON TEC Shockwave LED

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| PRINCETON TEC Shockwave LED|
The Shockwave LED uses a trio of three-watt MaxBright LED bulbs with Princeton Tec's exclusive collimator optics to produce a focused beam with a smooth, even hot spot. It was the brightest LED light we tested--the bright hot spot goes head-to-head against HIDs for intensity with an EV of 8.6 and still maintains 60 percent of its max brightness 12 inches out from center. The locking on/off switch operates in full or half-power modes, offering 12 hours and 20 hours of burn time, respectively. At depth, the light appeared blue-white with a medium-sized hot spot. The combination of luminance, burn time and an economical price ($129.99), make this both a Testers' Choice and a Best Buy.

GREEN FORCE FII HID 50

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| GREEN FORCE FII HID 50|
Green Force lights have a modular design that offers excellent function and flexibility. All Green Force battery packs accept all the company's light heads, like a camera that can accept many lenses, so you can mix and match components to create your perfect light. This combination matches an FII battery pack with the HID 50 light head, which is a 10-watt bulb with the stated equivalent brightness of a 50-watt halogen. Our light meter test showed it to be one of the brightest with an EV of 8.5 at the center of the hot spot and 6.5 at 12 inches out from center (76 percent of max brightness). Under water, the pool of light was smooth and even with a blue-white color and a large hot spot. You turn the light on and off by twisting the light head, which is sealed by three O-rings. The NiMH rechargeable batteries offer a long burn time (four hours) and can be recharged in two to three hours. A 21-watt HID Compact 100 light head is also available (EV 9.0 at the hot spot; 7.0 at the periphery), but offers less burn time than the HID 50. The FII HID 50 comes with a lantern handle or optional umbilical cable that converts your handheld into a canister-style light.

GREEN FORCE Flexi Fun Star

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| GREEN FORCE Flexi Fun Star|
The Flexi Fun Star is a new LED light option from Green Force that offers a more compact battery compartment, longer burn time, the convenience of AA-alkaline batteries and a price that's less than half that of the FII HID 50. It's no lightweight in brightness, though. A single three-watt LED bulb projects a smooth, even beam that registers an EV of 8.5 at the center, but drops off to 3.0 a foot out. This indicated a tightly focused beam, which is exactly what it produced when we took it under water. The eight AA-alkaline batteries provide an amazing 16 hours of burn time. Although the battery compartment is more compact, it accepts all other Green Force light heads, so you have the option to upgrade as needed. You can also choose NiMH rechargeable batteries or install the umbilical cable.

UNDERWATER KINETICS Sunlight C8 eLED

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| UNDERWATER KINETICS Sunlight C8 eLED|
Evolved from the original C8, this new LED-powered beam has all the brightness with added burn time. The C8 eLED cranks out a white hot spot with an EV of 8.3 on full power. The locking switch offers a half-power setting if you need more than 7.75 hours of burn time. During our dive, the white-colored hot spot was solid, but dropped off quickly away from the center. The long burn time, full/half-power locking switch and bright hot spot make it a Testers' Choice.

Primary Lights - Very Good Performers

NOCTURNAL LIGHTS SL3500

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| NOCTURNAL LIGHTS SL3500|
Afraid of the dark? You won't be with the Nocturnal SL 3500, the biggest, baddest and overall brightest HID light we tested. The hot spot recorded a blistering 10.5 EV and maintained a value of 8.0 EV at the one foot from center mark. The 35-watt HID bulb puts out a blue-white light, but draws some serious power giving a burn time of only one hour on the rechargeable NiMH battery pack. Under water, the coverage of light was unsurpassed, but that's to be expected from a light that's 10 inches long, four inches in diameter and tips the scales at more than five pounds. The base is sealed by double O-rings and twists off to allow access to the rechargeable NiMH battery pack. The on/off switch lacks a locking mechanism, but the company is considering designs that will incorporate one.

TEKTITE SeaRay-12

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| TEKTITE SeaRay-12|
The Tektite SeaRay-12 is proof that big light can come in a little package. This was the smallest primary light we tested--it fit easily into our BC pockets--but still produced a generous amount of light. The brightness comes from three four-watt LED bulbs and a lens/reflector combination that produces a broad, white light. It produced an EV of 8.0 at center and maintained 62 percent of its brightness with 5.0 EV at 12 inches out. The twist-on/twist-off end cap is protected with a double O-ring seal to keep water out of the anodized aluminum body. One of the reasons the light is so compact is that it runs on four of those tiny, expensive CR123A lithium batteries designed for cameras. According to Tektite, you can expect burn time at max brightness of about one-and-a-half hours on each set of batteries.

GREEN FORCE Flex II Tri-Star

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| GREEN FORCE Flex II Tri-Star|
The Tri-Star uses three one-watt LED bulbs to generate a wide, soft beam that extends smoothly out from the hot spot. Its beam was one of the widest we tested, retaining 68 percent of its modest brightness at one foot from center. Under water, we found the broad beam worked best as a floodlight for up-close observation. The Flex II NiMH battery pack provides 14 hours of burn time with the twist-on Tri-Star light head. The Green Force universal design accommodates other light head and battery options.

UNDERWATER KINETICS Sunlight C4 eLED

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| UNDERWATER KINETICS Sunlight C4 eLED|
The C4 eLED is a new version of the time-tested C4 xenon light, only with a brighter beam and a longer burn time. The hot spot produced a blue-white light with an EV of 7.8 at center compared to the yellow beam of the xenon at 7.0 EV. The LED has a burn time of 6.5 hours compared to four hours with the old version, and using the half-power option of the on/off switch you can extend it even longer. This small pistol-grip light was easy to operate even with gloves and could be used as a backup or carried in a BC pocket for daytime use.

{mospagebreak}Backup Lights - Testers' Choices

Backup lights have to be small, bright, durable and reliable. Their job is mostly to go unnoticed in a BC pocket until they are needed. They have to function when your primary has taken a dive and you need to be able to read your gauges, signal your buddy and get back to the boat. They might even work the day shift looking under ledges and pointing out critters. Most have a narrow, focused beam to put the most light into a sharp spot. Due to their size and limited battery power, they won't be able to cover a broad area, but LED technology has improved the intensity and durability of these backup blazers.

SARTEK 4000-D

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| SARTEK 4000-D|
The 4000-D was one of the brightest pocket lights tested, and with an EV rating of 7.0 at center, it could be used as a primary light in clear conditions. At depth, the light shows a blue focused beam. It's also one of the most durable lights we tested, with a solid aluminum body and a double O-ring twist-on/twist-off light head--think of a Mag light for Capt. Nemo. The 4000-D uses three D-cell alkaline batteries that are inexpensive and easy to find. The Luxeon III Star LED bulb cranks out at least 20 hours of maximum light per set of batteries, making it a Testers' Choice.

TEKTITE SeaRay-4

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| TEKTITE SeaRay-4|
This supercompact beam is one of the smallest backup lights we tested, but it produced the brightest beam in its class. The Luxeon III Star LED bulb is powered by two CR123A lithium batteries, which provide only two hours of burn time but offer a long shelf life (about five years). This is a great choice for those who keep their backup light in a BC pocket and forget about it until they need it. The end cap provides an on/off function with double O-ring seals on the durable aluminum body. The combination of size, brightness and battery shelf life make it one of our Testers' Choices.

PRINCETON TEC Impact XL

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| PRINCETON TEC Impact XL|
The Impact XL produces a strong blue-white light, reading 6.0 EV at the center hot spot. Powered by four AA alkaline batteries, this light far and away outlasts the others with 50-plus hours of burn time. The Impact XL worked well as a pointer under ledges and shelves with its spotlight beam. Having the lowest retail price in its class ($34.95) makes the Impact XL a Best Buy as well.

Backup Lights - Very Good Performers

SARTEK 4000-C

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| SARTEK 4000-C|
Like its big brother the 4000-D, this Sartek uses a Luxeon III Star LED bulb, but is powered by three C-cell alkaline batteries, giving off about the same amount of light for half the burn time. This slightly smaller version is also made from solid aluminum with double O-ring seals at the twist-on/twist-off light head. The hot spot is white and even with an EV of 6.7 at the center.

GREEN FORCE Diamond Back Up

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| GREEN FORCE Diamond Back Up|
Bright, compact and durable describe this pocket light from Green Force. A triple O-ring seal protects the twist-on/twist-off light head. Attachment holes in the base or the optional pouch make for multiple placement options. The nine-hour burn time and 5.4 EV reading at the center of an even hot spot make this a Very Good choice.

TEKTITE SeaRay-2

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| TEKTITE SeaRay-2|
Named for the two-watt Luxeon Star LED bulb it contains, this light offers less light but a slightly longer burn time than its big brother, the SeaRay-4. This light is otherwise identical in size, durability and function. It has a somewhat lower retail price, but we recommend coughing up the few extra clams to get the SeaRay-4, which offers a brighter hot spot.

UK Mini Q 40 eLED

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| UK Mini Q 40 eLED|
This light is built on the body of the popular Mini Q 40 backup light, complete with a mask strap attachment for hands-free operation. The Mini Q 40 eLED lasts longer (10 to 12 hours on a set of four AA batteries) than the incandescent version, thanks to a one-watt LED bulb.

AQUATEC Aqua-Star

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| AQUATEC Aqua-Star|
The cigar-sized Aqua-Star LED Torch is the smallest and sharpest-looking of the pocket lights we tested. Brightness is about average with a center EV reading of 5.0, but you get five hours of burn time from a pair of AAbatteries. The twist-on/twist-off end cap offers two operating modes. Tighten the cap all the way for constant-on mode; or loosen until the light goes out, then press your thumb on the end cap to activate in push-button mode.

Tank Markers

Tank markers are the safety sausage of the night diver. When you're drifting away in a current and your primary light is out of juice, a good tank marker is your best hope. These reusable versions are also more eco-friendly than chemical glow sticks.

GLO-TOOB FX

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| GLO-TOOB FX|
The Glo-Toob FX is a durable, long-lasting and versatile tank marker/signal light. Offered in a variety of colors, the Glo-Toob will operate up to 80 hours, depending on which of the seven different modes you're using. The marker can be programmed to remain on constantly or operate in several different flashing modes including SOS. Virtually indestructible, the Glo-Toob bounced along, attached to our tank, flashing out its message for hours on its single 12-volt battery, earning a Testers' Choice rating.

AQUATEC LED Mini Light Stick

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| AQUATEC LED Mini Light Stick|
Mini Light Sticks put out max brightness in a variety of colors. Mini Light Sticks come in flashing or constant-on models with burn times of 50 hours and 15 hours, respectively. Sticks come with an extra set of three watch batteries and a lanyard. We liked the durable design and the low retail price ($19.99) enough to rate it a Best Buy.

A Colorful Option

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| LIGHT DIAGNOSTICS prototype|
Another advantage of LEDs: They also come in colors. And a company called Light Diagnostics believes colored LEDs are the secret to better underwater vision. They sent us a prototype of a new primary dive light that uses 12 multicolored LEDs to provide two different beams. Turned one way, the switch activates six blue LED bulbs for a focused beam that registers a respectable 8.5 EV at center and 5.5 EV at edge. Turned the other way, the switch activates a bank of six LED bulbs of various colors to produce a wider "warm white" beam with a reddish tone. The company says the blue penetrates the water for distant viewing and the red beam improves underwater color rendering. For more information, contact Light Diagnostics, (801) 293-9266, web: www.lightdiagnostics.com.