BigBlue 3800 Lumen Narrow Beam Technical Light - Black

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 TL3800P has an 8° beam angle, which is a tight spot rather than a flood. That concentration gives it long throw and good penetration through particulate, so it works well for technical and wreck diving, lighting distant structure, inspecting line and signaling a buddy. For wide-angle coverage such as video or general reef lighting, a wider beam light is the better tool.

Bigblue rates the TL3800P at 1.5 hours on Level IV (3800 lumens), 3 hours on Level III (1900 lumens), 6 hours on Level II (950 lumens) and 15 hours on Level I (380 lumens). Continuous runtime at the highest intensity is listed as up to 2 hours. The color-coded battery level indicator on the push-button lets you check remaining charge before you splash.

The TL3800P runs on a rechargeable 32650 lithium-ion battery, which is included along with a USB charger. Charge time is 7 to 8 hours. The supplied USB charger also accepts 18650, 26650 and 32650 cells, so it covers more than one battery size.

Yes. The TL3800P light head, which Bigblue also sells separately, is interchangeable with other Bigblue light bodies including the VL2500P, VL2800P, VL3500P, VTL2500P, VTL2800P, VTL3100P and TL3100P. If you want to confirm the exact body you own will take this head, call or chat with us and we will check it with you.