Big Blue TL3800P and AL1300NP Technical Diving Combo Pack Narrow-Beam

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.

Bigblue lists the TL3800P primary at an 8 degree beam angle and the AL1300NP backup at 5 degrees. Both are narrow, focused beams intended for confined spaces such as caves and wrecks, and for cutting through murky, low-visibility water where a wide beam reflects off suspended particulate. Output is 6500K cool white in both lights.

Bigblue rates the combo pack to 100 meters (328 feet). On its standalone product page, the TL3800P primary is listed as tested to 150 meters. Both lights use anodized aluminum alloy housings, and the kit ships with spare O-rings and silicone lubricant so you can service the battery compartment seals as the owner's manual directs.

The kit includes two rechargeable Li-Ion batteries and two chargers: a BATCELL32650 cell for the TL3800P primary, which takes about 6 to 7 hours to charge, and a BATCELL18650 cell for the AL1300NP backup, which takes about 3 to 4 hours. Each light has its own charger, so no additional power accessories are needed to get diving.

The TL3800P has four levels: 3800 lumens for about 1.5 hours, 1900 lumens for about 3 hours, 950 lumens for about 6 hours and 380 lumens for about 15 hours. Across both lights in the pack, Bigblue quotes a 2 to 20 hour range depending on the setting. A color-coded battery level indicator on the TL3800P shows remaining charge.