Before you ever put your face underwater for a real dive, there’s a small language you need to learn. It’s not complicated, and it won’t take long, but knowing your scuba diving hand signals before you enter the water is one of those things that makes everything easier from your first breath underwater.
Diving hand signals exist because you can’t talk underwater. Every piece of important information, whether you’re OK, whether something is wrong, whether you’re running low on air, whether you’ve spotted something incredible, all of it gets communicated through your hands.
The signals are mostly universal across certification agencies, which means you can dive with someone who speaks a completely different language and still understand each other completely.
Here are the essential scuba diving signals every diver should know, from the first dive onwards.
Table of Contents
The OK Signal
This is the one you’ll use most. Form a circle with your thumb and index finger, keep the other three fingers extended upright. It means you’re fine, and it’s also how you ask your buddy if they’re fine. You’ll use this constantly, at the surface before descending, at depth when you check in, and every time your instructor looks at you.
Never answer with a thumbs-up. Underwater, thumbs up means ascend. It is not a positive response.
Up and Down
Thumb pointing upward means you want to ascend. Thumb pointing downward means you want to go deeper. These are essential scuba diving signs that you need to show clearly and wait for acknowledgment before moving.
Stop
Open palm facing forward, like a traffic stop gesture. Use it when you need your buddy to hold position. Respond to it immediately and hold still until you understand what comes next.
Problem or Not OK
Flat hand held parallel to the sea floor, rocked side to side. This is the “something isn’t right” signal, and when you see it, you stop what you’re doing and pay attention. Follow up by pointing to where the problem is.
Out of Air
The most critical of all scuba diving signals: one hand drawn horizontally across the throat, like a cut-off motion. This is an emergency signal. If you see it, move toward your buddy immediately and prepare to share air. If you need to give it, make it large and clear. Do not hesitate.
Share Air
Move your hand back and forth toward your regulator, then point to your buddy’s alternate regulator (the octopus). This is what follows an out-of-air signal, and it should be practised until it’s automatic.
Come Here / Follow Me
Extend your arm and beckon with your fingers, same as you would on land. You’ll use this when you’ve spotted marine life and want your buddy to come look, or when you’re leading a group and directing movement.
Ear Squeeze / Equalising
Pinch your nose with your thumb and index finger. This signals that you’re equalising pressure in your ears during descent, or that you’re having trouble equalising and need to slow down or stop. If you see your buddy give this signal, give them time. Never pressure someone to push through ear pain on a descent.
Help
A large sweeping wave of one arm above your head, big enough to be seen from a distance. Use it when you need immediate assistance and need to attract attention.
Safety Stop
One hand held flat and palm down. Show three fingers with the other hand underneath. This indicates a three-minute safety stop at five metres during ascent, which is standard practice at the end of most dives to allow your body to off-gas nitrogen safely.
A Few Practical Notes
Before any dive with a new buddy, run through the key scuba diving signals together at the surface. Takes about two minutes and removes all ambiguity underwater. This is especially worth doing if you’re diving with someone for the first time or in lower visibility conditions.
What indicates scuba diving or snorkeling from the surface is a related question worth knowing too: divers signal to boats and the surface using a large arm wave, while a surface marker buoy (SMB) indicates an ascending diver below. Learn to recognise both.
If you’re new to diving and want to learn all of this in context, with pool time, briefings, and open water dives, the Open Water course at La Bombona covers everything at 11,000 THB over about 3.5 days. Details at lbdivingkohtao.com/open-water.
