Learn These 20 Common Scuba Diving Hand Signals

Oceania, Micronesia, Yap, Diver with grey reef sharks, Carcharhinus amblyrhynchos
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When you're scuba diving with friends and you need to communicate underwater, knowing these 20 common scuba diving hand signals can really come in handy and more importantly, keep you safe. It's a very important "second language" for anyone who dives. Many of these hand signals are similar to common gestures and are easy to learn.

01
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'OK'

Photo of a diver communicating "okay" underwater.
Natalie L Gibb

The first-hand signal that most scuba divers learn is the "OK" hand signal. The "OK" signal is made by joining the thumb and index fingers to form a loop and extending the third, fourth and fifth fingers. This signal can be used as both a question and a response. The "OK" sign is a "demand-response" signal, meaning that if one diver asks another diver if he is OK, he must respond with either an "OK" signal in return or with the communication that something is wrong. The "OK" hand signal should not be confused with the "thumbs-up" signal, which in scuba diving means "end the dive."

02
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'Not OK' or 'Problem'

How to make the problem sign in scuba diving.
Natalie L Gibb

Scuba divers communicate a problem by extending a flattened hand and rotating it slowly side to side, similar to how many people signal "so-so" in a normal conversation. A diver communicating a problem underwater should then point to the source of the problem using his index finger. The most common use of the "Problem" hand signal is to communicate an ear equalization problem. The "ear problem" signal is taught to all student divers before they enter the water for the first time. 

03
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'OK' and 'Problem' on the Surface

How to communicate okay and problem in the surface when scuba diving.
Natalie L Gibb

During the open water course, scuba divers also learn how to communicate "OK" and "Problem" on the surface. These surface communication signals involve the whole arm, so that boat captains and surface support staff can easily understand a diver's communication from far away.

The "OK" sign is made by joining both arms in a ring above the head, or, if only one arm is free, by touching the top of the head with the fingertips. The "Help" or "Problem" signal is made by waving the arm over the head to call for attention. Don't wave "hi" to a dive boat on the surface because the captain is likely to think you need assistance.

04
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'Up' or 'End the Dive'

The "up" underwater communication for scuba diving.
Natalie L Gibb

A "Thumbs-Up" sign communicates "up" or "end the dive." This should not be confused with the "OK" signal. The "Up" signal is one of the most important signals in scuba diving. The Golden Rule of Scuba Diving states that any diver can end the dive at any point for any reason by using the "Up" signal. This important dive safety rule ensures that divers are not forced beyond their comfort level underwater. The "Up" signal is a demand-response signal. A diver who signals "Up" to their buddy should receive the "Up" signal in return so that he can be sure that their signal was understood.

05
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'Down'

The descend hand signal for scuba diving
Natalie L Gibb

The "Thumbs-Down" hand signal communicates "go down" or "descend" underwater. This signal should not be confused with the "Not-OK" hand signal used to indicate a problem. The "Down" signal is used in the first step of the Five-Point Descent, in which divers agree that they are prepared to begin to go deeper.

06
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'Slow Down'

How to communicate slow down underwater
Natalie L Gibb

The "Slow Down" hand signal is another basic signal that is taught to all student divers before their first scuba dive. It is made with the hand held out flat and motioned downward. Instructors use this signal to tell enthusiastic students to swim slowly and enjoy the incredible underwater world. Not only does swimming slowly make diving more fun, it also helps to avoid hyperventilation and other dangerous underwater behaviors.

07
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'Stop'

How to communicate stop and hold underwater.
Natalie L Gibb

Divers typically communicate "Stop" in one of two ways. The first method of communicating "Stop" (common in recreational diving) is to hold up a flat hand, palm forward, as shown on the left of the photo.

Technical divers, however, favor the "Hold" sign, shown on the right, made by extending a fist with the palm-side of the fist facing outward. The "Hold" sign is a demand-response signal: A diver who signals "Hold" to their buddies should receive a "Hold" sign in return, indicating that his buddies have understood the signal and agree to stop and hold their position until otherwise indicated.

08
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'Look'

How to Communicate "Look at" underwater.
Natalie L Gibb

The "Look at" hand signal is made by pointing the index and third fingers at your eyes and then indicating the object to be observed. A scuba instructor uses "Look at me" to indicate that students should watch him demonstrate an underwater skill, such as ​mask clearing during the Open Water Course. "Look at Me" is signaled by making the "Look" signal and then gesturing toward your chest with a finger or thumb (upper right).

Divers can also enjoy showing each other aquatic life and other underwater attractions by using the "Look Over There" signal, made by signaling "Look" and then pointing toward the animal or object (lower right).

09
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'Go in This Direction'

The "Go in This Direction" Hand Signal for Scuba Diving
Natalie L Gibb

To indicate or suggest a direction of travel, scuba divers use the fingertips of a flattened hand to point out the desired direction. Using all five fingers to point out a direction of travel helps to avoid confusion with the "Look" signal, which is made by pointing with a single index finger.

10
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'Come Here'

The Come Here Hand Signal for Scuba Diving
Natalie L Gibb

The "Come Here" hand signal is made by extending a flattened hand, palm up, and bending the fingertips upward toward yourself. The "Come Here" signal is basically the same signal that people use to indicate "come here" in everyday conversation. Scuba diving instructors use the "Come Here" signal to call students together or to show divers an interesting underwater attraction.

11
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'Level Off'

The Level Off hand signal for scuba diving.
Natalie L Gibb

The "Level Off" hand signal is used to communicate "remain at this depth" or "maintain this depth." The "Level Off" signal is most commonly used to communicate that divers have reached the planned maximum depth for a dive or to tell divers to hold previously designated depth for a safety or decompression stop. The "Level Off" hand signal is made by extending a flattened hand, palm down, and slowly moving it side to side horizontally.

12
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'Buddy Up' or 'Stay Together'

The Buddy Up hand Signal for Scuba Diving
Natalie L Gibb

A diver places two index fingers side by side to indicate "Buddy-Up" or "Stay Together." Scuba diving instructors use this hand signal to remind student divers to stay close to their buddies. Divers also occasionally use this signal to reassign buddy teams underwater. For example, when two divers in a group are low on air and ready to ascend, they can communicate "we'll stay together and ascend" using the "Buddy Up" hand signal.

If divers plan to reassign buddy teams based on air consumption underwater, the practice should be discussed and agreed upon by all divers in the group before the dive. No diver should even be left without a buddy.

13
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'Safety Stop'

How to communicate "Safety Stop" underwater while diving.
Natalie L Gibb

The "Safety Stop" hand signal is made by holding the "Level Off" signal (a flat hand) over three raised fingers. A diver is indicating "Level Off" for three minutes (signified by the three fingers), which is the minimum recommend time for a safety stop.

The safety stop signal should be used on every dive to communicate within the dive team that the divers have reached the pre-determined safety stop depth and agree to maintain that depth for a minimum of three minutes.

14
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'Deco' or 'Decompression'

The Decompression signal for scuba diving.
Natalie L Gibb

The "Decompression" hand signal is commonly made in one of two ways-- either with an extended pinky or with an extended pinky and thumb (similar to a "hang loose" sign). Technical divers trained in decompression diving techniques use this signal to communicate the need for a decompression stop. Recreational divers should also be familiar with this signal.

Although recreational scuba divers should never plan to make a decompression dive without proper training, this sign is useful in the unlikely event that a diver accidentally exceeds their no-decompression limit for a dive and must communicate the need for an emergency decompression stop.

15
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'Low on Air'

The Low-On-Air hand signal for scuba diving.
Natalie L Gibb

The "Low on Air" hand signal is made by placing a closed fist against the chest. In general, this hand signal is not used to indicate an emergency but to communicate that a diver has reached the pre-determined tank pressure reserve for their dive. Once a diver communicates that he or she is low on air, he or she and their buddy should agree to make a slow and controlled ascent to the surface and end the dive by using the "Up" signal.

16
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'Out of Air'

The Out of Air Hand Signal for Scuba Diving.
Natalie L Gibb

The "Out of Air" signal is taught to all Open Water Course and Experience Course students so that they know how to react in the unlikely event of an out-of-air emergency. The chances of an out-of air emergency when scuba diving are extremely low when proper pre-dive checks and diving procedures are observed.

This signal is made by moving a flat hand across the throat in a slicing motion to indicate that a diver is cut off from their air supply. This signal requires an immediate response from the diver's buddy, who should allow the out-of-air diver to breathe from their alternate air-source regulator while the two divers ascend together.

17
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'I'm Cold'

The "I'm Cold" hand signal for scuba diving.
Natalie L Gibb

A diver makes the "I'm Cold" hand signal by crossing their arms and rubbing their upper arms with his or her hands as though he or she is trying to warm him or her self.

This hand signal might seem frivolous, but it is not. If a diver becomes excessively chilled underwater, he could lose reasoning and motor skills. Plus his or her body will not eliminate absorbed nitrogen efficiently. For these reasons, it is imperative that a diver who begins to feel excessively chilled communicate the problem using the "I'm Cold" hand signal, end the dive, and begin his or her ascent to the surface with his or her dive buddy.

18
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'Bubbles' or "Leak'

How to communicate "bubbles" or "leak" underwater.
Natalie L Gibb

The "Bubbles" or "Leak" hand signal is used to communicate that a diver has noticed a leaking seal or bubbling piece of gear either on himself/herself or his or her buddy. Once a leak has been observed, divers should end the dive and begin a slow and controlled ascent to the surface.

Scuba diving has a very good safety record, but it is an equipment-dependent sport. Even small bubbles can indicate the beginning of a potentially serious problem. A diver makes the "Bubbles" hand signal by opening and closing his or her fingertips rapidly.

19
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'Question'

The "Question" hand signal for scuba diving.
Natalie L Gibb

The "Question" signal is made by raising a crooked index finger to mimic a question mark. The "Question" signal is used in conjunction with any one of the other scuba diving hand signals. For example, the "Question" signal followed by the "Up" signal could be used to communicate "Should we go up?" and the "Question" signal followed by the "Cold" signal could be used to express "Are you cold?"

20
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'Write It Down'

The hand signal for "Write It Down" when scuba diving.
Natalie L Gibb

When all other communication fails, divers sometimes find it easiest to simply write down the information to be communicated on an underwater slate or wet-notes underwater notebook. A writing device is a valuable tool underwater, and it can save time and increase diver safety by allowing a diver to express complex ideas or problems. The "Write It Down" signal is made by pantomiming that one hand is a writing surface and the other hand is writing with a pencil.