Scuba Diving Hand Signals & Underwater Communication

So you want to learn or review scuba diving hand signals or general underwater communication?

Great! Let’s do it!

Hand signals during scuba diving are our primary way to communicate with each other underwater. Without them, we would not know how much air our dive buddy has or when the dive instructor plans to ascend to the surface.

Every diver learns these hand signals before their first dive in open water. However, it always helps to review them on a regular basis.

Moreover, some hand signals may be different depending on the location you’re diving at, or the scuba training agency you dive with!

Here is our guide to scuba hand signals in 2024:

Ways to Communicate Underwater

Hand Signals

Hand signals are the primary method of underwater communication we use as scuba divers. They are easy to understand and you’ll learn them during your Open Water Diver course.

Light Signals

In darker environments like in cave diving or night diving, we can use dive lights to communicate. Quick flickers or circling motions with the dive light can get another diver’s attention and there are numerous other signals.

Writing Slates

Dive instructors and technical divers especially use writing slates for more complex messages.

These can be used to jot down information like dive times, depths, or any other specifics that cannot be easily conveyed with hand signals. In technical diving, they can also be used to mark decompression stops and procedures.

Electronic Communication Systems

Some full-face masks can house underwater communication systems similar to walkie-talkies. They are common in the military, combat diving, and saturation diving, however, have also become regular occurrences in scientific diving and for filmmakers.

They usually work over medium distances but require some fine-tuning.

Common Hand Signals in Scuba Diving

You’ll learn all the important underwater hand signals during your Open Water Diver course. Here are the most important ones to review or practice for your next dive trip:

1. “OK” or “All is Well”

Hand Signal: The tip of the index finger touches the tip of the thumb, creating a circle. The remaining fingers are extended.

Description: This is a universal signal that indicates everything is going as planned. It is often the first and last signal exchanged between divers.

2. “Problem” or “Something is Wrong”

Hand Signal: A flat hand is waved horizontally back and forth.

Description: This signal indicates that there is a problem. The nature of the problem is usually communicated immediately after this signal.

3. “Stop”

Hand Signal: The hand is extended with the palm facing outward, much like a stop sign.

Description: This is used to indicate that one should halt their movement or actions.

4. “Go Up” or “End the Dive”

Hand Signal: Thumb pointed upward. Description: This signal is used to indicate that the diver should ascend to the surface or shallower depth.

5. “Go Down”

Hand Signal: Thumb pointed downward.

Description: This is used to signify that it’s safe to descend or continue descending.

6. “Look at Me”

Hand Signal: The index and middle finger form a “V”, point towards the eyes and then towards the individual who needs to pay attention.

Description: This is to catch another diver’s attention and direct their gaze towards you.

7. “Look” or “See”

Hand Signal: The index and middle fingers form a “V” and are then pointed in the direction you want the other diver to look. Description: This is used to direct attention to a specific object or area.

8. “Low on Air”

Hand Signal: A closed fist is placed against the chest. Description: This indicates that a diver is low on air and the dive needs to be terminated soon.

9. “Out of Air”

Hand Signal: A hand is drawn across the throat.

Description: This is a critical signal indicating immediate danger due to lack of air.

10. “Safety Stop”

Hand Signal: An open hand is placed over the head.

Description: This is used to indicate that a safety stop is needed, usually at 15 feet for 3 minutes to off-gas nitrogen before surfacing.