Dive lights: what to look for

Even in the middle of the day, the things you can’t see are often under rock overhangs and in nooks and crannies that look dark from the outside. A light shows you what’s hiding there.

Four jobs, four lights

• Primary light: your main light for night dives and looking into holes and under ledges.
• Backup light: a small second light every night diver carries, in case the primary fails.
• Marker light: a small light on your tank or BCD so your buddy can see you in the dark.
• Video light: a wide, even beam for filming. See our underwater photo guide.

The responsible way to do a night dive is with all three: a primary, a backup and a tank marker light.

How much light do you need?

To be honest, you can never have too much light, and it often comes down to budget.

• Around 250 lumens: you’re into decent lights.
• Around 450 lumens: even better.
• 1,000 lumens and up: solid lights that work for both day and night dives.

Beam and brightness

More lumens don’t necessarily mean better. Each beam style has its purpose.

• Narrow (spot) beam: a bright narrow beam usually lets you see farther in murky water and reaches into holes. Best for a primary.
• Wide beam: lights up a whole scene evenly, which is best for video. In murky water, though, a bright wide beam just lights up the silt right in front of you.
• Brighter isn’t always better: a very bright light also lights up every particle in the water. Balance brightness with burn time.

Batteries

• Rechargeable: most companies are moving this way, so we’re not throwing away a pile of batteries. Usually brighter and cheaper to run.
• AA or other standard batteries: easy to find anywhere you travel.
• Flying: spare lithium batteries go in your carry-on, not your checked bag (see the FAA’s lithium battery rules). We carry all our batteries in the cabin.

How lights usually die

• They flood, because O-ring maintenance and lubrication were ignored.
• The LED burns out, because the light was left on out of the water for way too long. The water keeps it cool; in the air, it overheats.

Care

Check the O-ring before every dive, rinse the light in fresh water after, and store it with the batteries out. Turn it on only when you’re about to get in.

At night

Blinding your buddy is totally avoidable: never shine your light in their face. Keep the beam on their chest or down. Light signals and the rest of night diving are covered in our Night Diver course.