When diving at night, every diver should have three lights.

The first is your primary torch, turned on at the start of the dive and the brightest light you carry. The second is a backup, usually smaller and cheaper, in case your primary fails.

The third is the one most divers skip: a tank marker.

A tank marker attaches to your tank valve, regulator, or the back of your BCD.

It serves two purposes.

On the surface, it makes you visible to boats and other divers.

Underwater, it helps your buddy find you.

In this article, I'll cover what the best options for tank markers are, so you can buy the best one for your next dive.

Best Tank Markers

• Best Budget Tank Marker: Orcatorch SD01Pro
• Best for Dive Businesses : Glow Mind Emergency Glow Sticks
• Best Personal Luxury Tank Marker: XS Scuba LED Glowstick

Best Overall: ORCATORCH SD01PRO

The ORCATORCH SD01PRO is the tank marker I'd hand to any diver asking for a recommendation.

It's compact, runs on a single AAA battery, waterproof to 150 meters, and gives you two mode being a constant and slow flash.

The constant mode runs for 37 hours and the flash mode stretches to 70.

At 25 grams and just over 3 inches long, it's very compact.

It comes in five colors, white, green, blue, red, and orange, so your buddy group can each pick a different color and be identified underwater without surfacing to check.

Best Budget Pick: Glow Mind Emergency Glow Sticks

If you night dive occasionally and don't want to invest in a reusable marker yet, a pack of chemical glow sticks is a practical solution. I see these a lot with dive charters, businesses, and guides, as it's not practical to have tank markers for every single diver.

The Glow Mind sticks run for 12 hours, covering any reasonable dive or multi-dive night, and they're waterproof and visible from over a mile away.

The main tradeoff is that they're single-use.

Once activated, that's it. But at $11.96 for a 12-pack, the cost per dive is low enough that it's not a real objection for most people.

They're individually wrapped to prevent accidental activation and have a long shelf life, so you can stock up and keep them in your kit bag year-round.

They're also non-toxic and non-leaking.

Best for Frequent Divers: XS Scuba LED Glowstick

The XS Scuba LED Glowstick is built for diving and the brighest option on the list. The mounting strap attaches it directly to your regulator first stage.

A single LED powers 14 light-emitting fibers, giving it a glowstick look underwater while being fully reusable.

It runs on three LR44 alkaline batteries included in the box and comes in five colors for personalization and diver identification.

Tank Marker Buying Guide

Reusable vs. Disposable

The biggest decision when choosing a tank marker is whether you want something reusable across hundreds of dives or something you crack and toss.

Chemical glow sticks are single-use. They're cheap, require no batteries, and need zero maintenance, but every dive costs you another stick. For a diver who night dives a few times a year, that's not a problem. For someone logging regular night dives, the cost and waste adds up quickly.

LED markers run on replaceable batteries and can last for years. The upfront cost is higher, but the cost per dive drops to near zero once you own one. If you night dive with any regularity, a reusable LED marker makes more financial sense within the first season.

Brightness and Visibility

Not all markers are equally bright, and visibility matters both underwater and on the surface.

Chemical glow sticks produce 360-degree illumination, which is useful for being seen from all angles. LED markers are typically more directional but can be significantly brighter.

For underwater use, brightness is less critical than color consistency, since water filters light as depth increases. For surface visibility, the Glow Mind sticks claim visibility over a mile, which covers any recreational dive scenario.

Battery Life

For LED markers, battery life determines how much planning you need before each dive.

A marker that lasts 37 hours on a single AAA battery means you're not thinking about this very often. A marker that lasts only a few hours per battery needs more attention, especially on liveaboards or multi-day trips where you're diving every day.

Check that the battery is a standard size like AAA or LR44. Standard batteries are easy to replace anywhere in the world. Proprietary batteries are not.

Attachment and Mounting

How a marker attaches to your kit affects how useful it is underwater.

A marker that clips to a BCD D-ring is easy to attach but can shift around on the dive. A marker that mounts directly to your first stage or cylinder stays in a fixed position and is more reliable for buddy identification.

The XS Scuba LED Glowstick includes a dedicated mounting strap for the first stage. The ORCATORCH SD01PRO uses a clip. Chemical glow sticks need a separate clip or band to secure to your kit, which is worth buying in advance.

Color and Buddy Identification

If you're diving in a group, color coordination is one of the most practical uses of a tank marker.

Assign each diver a different color and you can identify your buddy from a distance without surfacing or shining a light in their face. Green is the most common and most visible color underwater, but any consistent color works as long as your group sticks to the system.

If you're diving solo or as a pair, color matters less.