Scubapro Novalight 850 Tec Single-Mode Torch Dive Light

Lumens measure the total light output, but they say nothing about how that light is shaped, so a tight narrow beam can look far brighter at distance than a higher-lumen wide beam. Beam angle, color temperature, and water clarity affect what you actually see as much as the lumen figure does. Use lumens to compare lights of a similar beam type rather than as a single score of quality.

A primary light is your main light, usually brighter, larger, and with a longer burn time, while a backup is a small, simple light carried in case the primary fails. Any dive where you need a light to exit safely, such as a night dive, calls for carrying at least one backup. Backups are chosen for reliability and simplicity rather than for maximum output.

Burn time and brightness trade directly against each other, so the same battery run at a lower power setting lasts substantially longer. Manufacturers usually quote burn time at each power level, and many lights automatically step down output as the battery drains or the head heats up. Treat quoted figures as fresh-battery, ideal-condition numbers and plan for more burn time than your dive actually needs.

The o-rings sealing the battery compartment are what keep the light from flooding, so inspect them for grit, hair, and nicks every time you open it, and wipe the sealing surfaces clean. Lubricate lightly with the grease type the manufacturer specifies, using a thin film rather than a heavy coat, because excess grease attracts sand. Replace o-rings when they look flattened, cracked, or dry, and do not over-tighten the cap in the hope of sealing a bad o-ring.

Lithium batteries are subject to airline and regulatory limits that vary by cell chemistry, watt-hour rating, and whether the cells are installed or loose. As a general rule lithium cells travel in carry-on baggage rather than checked baggage, with terminals protected against short circuit, but you must confirm your airline's current policy and any local rules before you fly. Carrying the manufacturer's battery specification sheet helps if you are questioned at screening.

Rinse it in fresh water after each dive day and work the switch while it is submerged so salt does not crystallize inside it, then dry it before opening. For storage, remove or charge the batteries as the manual directs, and leave the cap loose so the o-ring does not take a permanent set. Never store a light with corroded or leaking cells inside it.

Test it briefly as part of your pre-dive check, but do not leave a powerful light running in air, because many are designed to shed heat into the water and can overheat on the surface. Check the manual, as some lights have thermal protection that dims or shuts them down when they are dry. Testing before you gear up is far better than discovering a dead light at depth.

The Nova 850 Tec runs on 3 standard C-size batteries, and you can use either rechargeable or disposable cells. Batteries and a charger are not included with the light, so plan to supply your own. Scubapro quotes approximately 7 hours of burn time on a set of cells. The light has double O-ring seals and an over-pressure valve for battery off-gassing safety.

Scubapro rates the Nova 850 Tec at 850 lumens and 17,000 lux measured at 1 m, which comes from concentrating the output into a narrow 8 degree beam. That tight cone is designed for probing dark compartments in wrecks and hidden crevices rather than lighting a wide scene. Actual visible reach still depends on water clarity and particulate, so treat the lux figure as a comparison tool.

No. It is a single-mode light, so one twist of the head turns it on at full 850 lumen output and another twist turns it off. There is no dimming, no strobe mode and nothing to cycle through with gloved hands. Divers who want a simple, repeatable light with approximately 7 hours of burn time tend to prefer this layout.

The light has a dedicated attachment point for a bolt snap, which lets you clip it to a D-ring on your BC or technical harness when your hands are busy. A bolt snap is not listed among the included items. The body measures 9.6 x 1.8 in (243 x 45 mm) and weighs 13.3 oz / 378 g with batteries installed, so it stows easily on a chest or shoulder D-ring.