Sherwood 2800 Lumen Flashlight

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.

Sherwood rates the ST2800 at 1.5+ hours at 100% output, 2.5+ hours at 50% output and 2 hours in SOS strobe mode. A full recharge takes about 6 hours through the built-in USB charger. The Visual Charge Indicator helps you track state of charge between dives: green for full, amber for half and red for low.

Yes. The ST2800 uses a rechargeable 26650 removable lithium-ion cell, so the battery can be taken out of the aluminum body rather than being sealed inside. The light also charges in place through its built-in USB charger using the included USB cable, so you do not need an external charger for normal use.

The ST2800 is depth rated to 328 feet (100 meters), which covers recreational and deep recreational diving. Sealing is handled by a multi-surface seal, and Sherwood includes an extra seal in the box for maintenance. The light is designed for underwater use only.

A 12 degree beam is a focused, narrow spot rather than a wide flood. That concentrates the 2800 lumens into a tight hot spot, which helps you look into wrecks, crevices and overhangs, see at distance in clear water and signal your buddy. Wide flood beams spread light for photography and video; this one prioritizes reach.