LIGHTS – Essentials of the GUE equipment configuration

THIS ARTICLE SERIES IS BASED ON THE GUE PUBLICATION

DRESS FOR SUCCESS BY DAN MACKAY

ADDITIONAL TEXT BY JARROD JABLONSKI

PHOTOS HALCYON DIVE SYSTEMS & JESPER KJØLLER

Diving lights, their integration into the configuration, and the protocols for their usage are essential elements deeply embedded in the philosophy of GUE. While certain equipment components have remained largely unchanged over the years—for instance, many divers still rely on the same pair of rubber fins and the steel backplate they invested in two decades ago—diving lights are built upon two evolving technologies: batteries and light sources. Let’s shed some light on the subject.

Diving lights provide not only the main source of illumination during diving operations but are also an effective means of diver communication.

The two common styles of diving lights are canister and cordless. The canister light is worn on the diver’s right-side waist with a cord that connects to the lighthead. This light is popular with technical, cave, and overhead divers because it has extended burn time and flexibility; it can be used with different lightheads, and it also functions to power heat for a drysuit.

Cordless lights, on the other hand, attach directly to the battery, which reduces complexity, risk of cord entanglement, and configuration challenges (particularly in sidemount diving when a hip-mounted light is difficult and cord routing problems can occur with butt-mounted canisters).

During their diving careers, tech and cave divers should develop familiarity and proficiency with both types of lights and, should the need arise, be skilled in managing a hip-mounted canister with a light cord.

Selection

When selecting a diving light, divers should look for a compact battery pack with an appropriate burn time for the planned dives. The lighthead should have a Goodman-style handle for easy management. If using a hip-mounted canister, ensure that the cord is long enough to reach from the right hip to the left hand without excess length. The primary light should provide enough burn time to complete the entire dive, with some reserve remaining. As a general rule, having 1.5 times the anticipated burn time is a good approximation. It is also beneficial to choose rechargeable batteries to minimize waste and allow for frequent use. Divers using cordless lights should be particularly aware of maintaining sufficient burn time due to the reduced energy density of these battery packs.

Stowage

A clip should be fixed permanently to the left side of the Goodman handle where it can be trapped by the diver’s left thumb during use, reducing the risk of entanglement when managing guidelines.

A loop should be fixed at the rear of the lighthead, allowing a double-ender clip to be temporarily attached. This position is a temporary stowage location that points the light beam downward, illuminating the surrounding area yet avoiding blinding dive buddies. This stowage position is useful when working with stage bottles or other equipment, as it also provides a backup way to secure the light should the primary attachment become compromised.

Fitting a canister light

Feed the right-side harness belt through the canister belt loop and slide the canister to within three to four inches of the backplate. Lock the canister in place by sliding a second SS belt buckle onto the belt, snug to the canister and locking it in place. The additional buckle prevents accidentally dropping the canister when removing a harness. When the light is not in use, clip it to the right-chest D-ring with the “permanent” clip on the side of the Goodman handle. Stow excess light cord securely under the waistband.

The primary light cord is neatly stored in the belt when not in use, and an extra belt buckle securely holds the canister in place.

Technology

Lighting technology has evolved considerably in recent years. The early history of underwater lights found divers using halogen lights, which had a filament that could easily be damaged and that also required significant power. The next generation high-intensity discharge (HID) lights greatly reduced energy consumption but still left divers with a vulnerable bulb. Modern-day lights are almost exclusively LED and provide great energy efficiency and brighter light output with superior durability. The “front-emitting” nature of the beam can complicate a tight focus, but recent technology has reduced this problem, adding a tight focus to the other benefits of LED technology.

LED design

LED stands for light-emitting diode. It is a semiconductor device that emits light when an electric current passes through it. They are known for their energy efficiency, long lifespan, and versatility in producing different colors of light. LEDs have become increasingly popular as a replacement for traditional incandescent and fluorescent lighting due to their lower energy consumption and environmental benefits. LED lights emit light from a diode where the light is distributed forward. This is different from halogen and HID lights, which emitted light mainly from the sides of an energized filament. In the latter design, light was collected