Scuba Diving Hand Signals

You can’t communicate with words underwater. When you want to ‘talk’ with your dive buddy, you need to use hand signals, a common language that you both understand.

These standardized gestures are the universal language of diving. They even let divers from different countries, backgrounds, and training organizations communicate clearly and effectively underwater.

So, let’s take a look at the diving hand signals every diver needs to know, from basic safety communications to specialized signals for marine life encounters and photography. These signals can make your scuba diving safer and more enjoyable.

Why Hand Signals Matter for Diving Safety

Underwater communication isn't just a convenience — it’s the best way to keep you safe when you dive. Effective communication between dive buddies is great for:

• Sharing important information about scuba equipment status
• Warning about potential hazards
• Coordinating movements and navigation
• Communicating physical or psychological concerns
• Sharing exciting marine life sightings
• Managing emergency situations

While some advanced divers use underwater writing slates or specialized underwater communication devices, hand signals are the primary and most reliable method of communication for several reasons.

They work regardless of technology failures

Unlike electronic communication devices, hand signals don't rely on batteries or equipment that can malfunction.

They are universally understood

Most basic diving signals are standardized across training agencies and geographical regions, so divers from different backgrounds can safely dive together.

They are immediate and attention-grabbing

A clear hand signal can quickly alert your buddy to important information without delay.

They require no additional equipment

Your hands are always with you. Hand signals are the most accessible form of underwater communication.

Essential Safety and Status Signals

The fundamental OK signal

The most frequently used diving signal is the "OK" sign, formed by connecting the thumb and forefinger in a circle with the remaining fingers extended. This signal says:

• As a question: "Are you OK?" when directed at another diver
• As a response: "I am OK" when given after being asked
• As confirmation: "OK to descend/ascend" when agreed upon during dive planning
• As a general status update during the dive

Dive professionals consistently watch for and use this signal throughout a dive to stay aware of each other.

The surface OK signal

An important variation of the OK signal is used while swimming at the surface. Since the standard OK hand signal may not be visible to distant boats or shore observers, the surface OK is performed by touching or connecting the hands above the head in a large circle or by extending one arm straight up (sometimes while touching the top of the head with the other hand).

This highly visible signal communicates to both nearby divers and distant observers that you're OK. This is important after surfacing from a dive when boats or shore personnel need to confirm your status.

Directional signals

Clear directional communication helps buddy teams navigate effectively. Some of the most common signals are:

• Directional indication: Point with the entire hand (not just a finger) in the direction you want to go. The extended hand with all fingers together creates a clear indicating plane that's more visible than a single finger.
• Level off/stay at current depth: Hold your hand flat, palm down, and move it in a horizontal plane, indicating "stay at this level."
• Go up/ascend: Thumb up with the hand closed, indicating controlled upward movement.
• Go down/descend: Thumb down with the hand closed, pointing toward deeper water.
• Turn around/go back: Make a circular motion with your extended forefinger.

Air and pressure status

You need to monitor breathing gas supply during every dive, and several signals allow divers to communicate information about this vital resource.

• How much air?: Tap your tank or the location of your pressure gauge to ask your buddy about their remaining air supply.
• Air supply status: In response to the air question, indicate your pressure by extending fingers. Different training agencies teach variations of this signal, but a common method is:

• Show a closed fist for each 1000 PSI/70 bar
• Then show the appropriate number of fingers for each 100 PSI/10 bar
• For example, 2700 PSI would be shown as two closed fists followed by seven extended fingers.

• Low on air/reserve reached: Hold a flat hand, palm down, and rock it back and forth in a seesaw motion at chest level. This indicates you've reached your predetermined reserve level (often 500-700 PSI/30-50 bar).
• Out of air/emergency air sharing: Move your flattened hand, palm down, across your throat in a cutting motion. This urgent signal indicates you need your buddy's alternate air source immediately.

Problem indication and assistance

When things aren't going according to plan, you want your dive buddies to know.

• Something is wrong: Extend your hand with a flat palm, rocking it side to side (like a "so-so" gesture). This general signal indicates a non-emergency problem that needs attention.
• I'm cold: Cross your arms across your chest in a hugging motion, indicating you're experiencing a cold that's affecting your comfort.
• Cramp: Make a fist with one hand and grasp it with the other, indicating muscle cramping. Often accompanied by pointing to the affected area.
• I need help/assistance: Extend and wave one arm. This is a general distress signal indicating you need your buddy's immediate attention and help.
• Danger: Make a closed fist with one hand and tap the top of your head repeatedly. This alerts others to potential hazards in the environment.
• Emergency/Panic: Waving both arms overhead, either underwater or at the surface, is a universal distress signal indicating an emergency situation requiring immediate assistance.

Dive progress and planning signals

Efficient buddy communication extends to coordinating the dive plan as it progresses.

• End the dive/Let's go up: Make a "cutting" motion across your throat with a flat hand. This doesn't indicate an emergency but simply communicates "this dive is finished" or "let's start our ascent."
• Safety stop: Hold your hand flat with fingers extended, palm down, and place the other hand above it with fingers spread, creating the "roof" of an imaginary house. This indicates performing a safety stop.
• Hold here/Stay together: Extend your arm with your palm facing out (like a "stop" gesture) to indicate that you are staying in the current position or grouping together.
• Level off: With your palm facing down, move your flattened hand in a horizontal plane, indicating that you are maintaining current depth.
• Check your instruments: Tap the location of your gauges to remind your buddy to check their depth, pressure, and dive computer.
• Slow down: With palms facing each other, move your hands slowly apart and together, indicating a need to reduce speed.
• Look/Pay attention: Point with two fingers from your eyes toward the object or direction of interest.
• Think/Calculate: Point to your temple, indicating a need to think about the situation or calculate something.

Marine life encounter signals

Part of the joy of diving is encountering marine creatures, and specialized signals help communicate these sightings.

• Shark: Place your flattened hand on top of your head, creating a "fin" shape. Move the hand forward to indicate the direction of travel.
• Turtle: Stack your fists on top of each other and move them in a swimming motion, mimicking turtle flippers.
• Ray/Manta: Cross your arms at the wrists with hands open and "flap" them like the wings of a ray.
• Dolphin/Whale: Make an arcing, undulating motion with your flattened hand, mimicking the animal's swimming pattern.
• Eel: Extend your arm and move your hand in a serpentine, S-shaped motion.
• Lobster/Crayfish: Hold your hands in front with fingers curled downward, then wave them forward like antennae.
• Octopus: Bunch your hand with fingers grouped together, then spread them outward repeatedly, mimicking the movement of tentacles.
• Cuttlefish/Squid: Place your hands together at the wrists with fingers extended and move them in a swimming/jetting motion.
• Fish (generic): Make a swimming motion with your hand, moving it forward with fingers together.
• Lionfish: Spread your fingers and move your hand downward, indicating the animal's distinctive venomous spines.
• Sea snake: Make a horizontal, side-to-side slithering motion with one hand.

Specialized Signals for Photography and Technical Diving

As you move to more specialized diving, your hand signals will evolve as well to more sophisticated gestures.

Photography signals

• Take my picture: Make a frame with your index fingers and thumbs, or mime pressing a camera shutter.
• Wait for photograph: Hold up one index finger in a "wait a moment" gesture when positioning for a photograph.
• Model/pose here: Point to the location where you want your subject to position themselves.
• Light/strobe needed: Mime flashing a strobe by opening and closing your hand quickly.

Technical diving signals

• Switch gases/change tanks: Mime reaching to valve positions or make a switching motion at chest level.
• Perform gas check: Tap the tank valve or regulator with an interrogative gesture.
• Start/end decompression: Make decompression-specific signals as established during the pre-dive briefing.
• Line placement/reel operation: Simulate handling a reel or line with your hands.
• Gas pressure in numbers: Technical divers often use specific number systems to precisely communicate remaining pressures.

Pre-Dive Signal Review and Customization

While most basic signals are standardized, variations exist between training agencies, geographical regions, and specialized forms of diving. You should pay attention to the pre-dive briefing and signal review, especially if you are:

• Diving with new buddies
• Diving in a new environment with specific hazards
• Engaging in specialized activities like photography, night diving, or technical diving
• Working with divers from different training backgrounds or countries

During the pre-dive briefing, take time to:

• Review and demonstrate the essential signals you expect to use
• Establish any specialized or custom signals needed for the specific dive
• Confirm everyone understands both the signals and the appropriate responses
• Establish backup communication methods if applicable

It's perfectly acceptable to create custom signals for specific needs as long as all divers in the group understand them. Many buddy teams develop their own signals for commonly encountered situations or marine life specific to their diving region.

Teaching Signals to New Divers

If you are diving with beginners or helping friends prepare for certification, emphasize these points about hand signals.

Make signals clear and deliberate

Underwater signals should be performed with clear, defined movements in the buddy's line of sight.

Confirm understanding

After giving or receiving a signal, confirm with an OK signal once the message is understood.

Don't rush communications

Take the time to check your message is received correctly, especially for important safety information.

Practice on land first

New divers should practice signals on land until they become second nature.

Watch your dive professional

Guides and instructors often use exemplary signal technique—observe and emulate their clarity and positioning.

The Connection Between Signals and Situational Awareness

The effective use of hand signals goes hand in hand with good situational awareness underwater.

Regular buddy contact

Position yourself where signals can be easily seen and exchange periodic OK signals.

Environmental awareness

Notice changing conditions that might require communication (current changes, thermoclines, navigation landmarks).

Group cohesion

In group dives, stay aware of all team members, not just your immediate buddy.

Task loading awareness

Recognize when you or others are dealing with multiple tasks that might affect signal clarity or responsiveness.

Hand Signals for Safe Diving

Hand signals are the safest way to stay in communication with your diving team and dive buddy. They are also the best way to share your experience and make your diving more enjoyable.

Before you dive, agree on the plan and follow the briefing. Take a note of hand signaling so that you can share information underwater. Hand signals keep you safe during your dive but they are also a shared language of discovery in the underwater world.

Hand signaling lets you communicate about air supply, point out a fascinating marine creature, or simply check that your buddy is enjoying the dive. Diving is a social experience, not just a sport or hobby, and hand signaling is the common language that keeps the team together. Learn it, practice it, and have fun!