Light Use for Communication

A dive light is more than just a tool for seeing—it’s one of the most powerful communication tools in a diver’s kit. Even in broad daylight, using a primary light for signaling can dramatically improve team coordination, especially in low visibility or overhead environments.

This page focuses on intentional light use as part of team communication, not just for illuminating the environment.

Why Use Lights for Communication?

Unlike hand signals, which require eye contact, a light beam can:

• Get a teammate’s attention from a distance
• Point to objects, hazards, or directions
• Signal issues when speaking or gesturing isn’t possible
• Maintain team awareness even when not looking directly at each other

Used intentionally, your light becomes part of your body language—another way to “speak” underwater.

In many dive locations, lights are used even in daylight. In the Chicagoland area, for example, divers often bring a primary light on every dive due to lower visibility in quarries and local lakes. Unlike tropical destinations with crystal-clear water, Midwestern sites often have reduced contrast, ambient haze, or dark bottom layers, making lights a practical communication tool—not just a backup.

Beam Discipline Matters

Poor light use creates confusion. Good light discipline ensures your teammates understand your intentions.

Best practices:

• Turn it on early. Don’t wait for darkness—use it for communication even in daylight.
• Don’t wave it randomly. Keep your beam steady unless signaling.
• Use it deliberately. Treat it as an extension of your hand, not a flashlight to sweep everywhere.
• Avoid blinding others. Keep the beam pointed ahead and down—not in your teammate’s face.

If you plan to hold your light throughout the dive, a Goodman handle makes a significant difference. It lets you keep the light secured on your hand while maintaining dexterity and minimizing hand fatigue. This becomes especially helpful when you need to signal, adjust gear, or handle a spool or camera.

Standard Signals With Lights

While not every team uses the same light language, many technical training agencies use a few common standards:

You should agree on signal meanings during the pre-dive briefing. Don’t assume everyone interprets signals the same way.

Light Positioning and Team Awareness

Your teammates should always be able to see your beam, even if they aren’t looking directly at you. This helps them know you’re nearby and in control.

Recommended approach:

• Keep your light beam just ahead and slightly below the lead diver
• Assign sides so beams aren’t overlapping
• When in formation, never sweep your beam sideways without intention
• In a single-file line, the rear diver uses the light to signal forward

This allows the lead diver to confirm everyone’s presence without turning around.

One-Handed Communication Becomes Essential

When one hand is holding a light, your ability to signal becomes more limited—so one-handed hand signals become essential. Most divers were originally taught two-handed signals, but underwater teams—especially those using lights—should practice:

• Gas checks
• Problem indicators

—all with one hand.

When to Use Light Instead of Hand Signals

• In low vis or dark conditions
• When your teammate is far away but within beam range
• When someone is task-loaded and can’t look at you
• To quietly attract attention without disturbing marine life or other divers

Light signals don’t replace hand signals—they complement them.

A Note on Light Compatibility

For effective communication, everyone in the team should be using primary lights with similar beam strength and focus. If one diver has a narrow beam and another has a wide flood, the signals may not be readable.