Dive light and torch buying guide: lumens, burn time and cost
Water swallows light and colour fast. A good dive torch brings the reef back to life and is non-negotiable for night dives. Here's how to choose one and what to pay.
Underwater, colour disappears with depth — red fades within the first few metres, and by 20 metres the reef looks blue-grey. A dive light brings it all back, throwing true colour onto coral and lighting up the cracks where the interesting creatures hide. For night dives it's not a nice-to-have, it's the dive. Even on day dives a compact torch turns a flat wall into a treasure hunt.
Primary vs backup lights
Most divers end up with a small system rather than a single torch:
- Primary light — your main, brightest torch for the dive. Bigger battery, longer burn time, wider or tighter beam depending on use.
- Backup light — a small second torch you carry in a pocket. If the primary dies on a night dive, this gets you home calmly.
- Beam angle — a narrow 'spot' beam punches through water and into holes; a wide beam suits photography and general lighting.
Never night dive on a single light
The unwritten rule of night diving: always carry a backup. A primary failure in the dark without a spare turns a fun dive into a stressful one. A small backup torch costs little and changes everything if your main light floods or dies.
Lumens and burn time: how to read the specs
Two numbers dominate the spec sheet, and bigger isn't automatically better:
- Lumens — total light output. 500–1000 lumens is plenty for recreational night dives; very high lumens mainly matter for video lights and murky water.
- Burn time — how long it runs at full power. You want comfortable margin over your dive length; a 60-minute dive needs well over 60 minutes of burn.
- Rechargeable vs disposable — rechargeable Li-ion saves money and waste over time; replaceable AA/battery models are convenient for travel and remote trips.
Don't chase lumens, chase the right beam
A focused 700-lumen spot often out-performs a flood twice as bright for spotting critters in crevices. For video you want wide and soft; for general diving you want a tight, punchy beam. Match the beam to the job before you compare numbers.
What a dive torch costs
Prices span a wide range depending on output and build. The tiers below are typical category ranges, not specific products — always compare live verified prices on DiveCost before buying.
| Budget / entryCompact backup or basic primary, modest lumens, AA cells. | €25–€60 |
| Mid-rangeRechargeable primary, 500–1000 lm, good burn time. | €60–€140 |
| PremiumHigh-output canister/video lights, long burn, tech-grade. | €140–€400+ |
| Sensible primary + backup | €80–€160 |
Care, flooding and travel
A dive light lives or dies by its o-rings and seals. Rinse in fresh water after every dive, grease the o-rings occasionally, and never open the battery compartment with wet or sandy hands. For flying, check airline rules on lithium batteries — many require them in carry-on, not checked luggage.
Keep spare o-rings for your torch in a save-a-dive kit so a flooded seal doesn't end your night diving. For the wider what-to-own question, see rent vs buy and what it costs. Famous night and muck dives await in Tulamben, Bali and around Koh Tao.
Bottom line: a dive light is the cheapest way to double the wonder of a reef and the only way to dive at night. Buy a sensible primary with comfortable burn time, always carry a backup after dark, look after the seals, and pick the beam to match your diving rather than chasing raw lumens.