Diving Signals – Hand and Light Sign System for Scuba Divers

Diving signals are a crucial aspect of scuba diving safety and communication, as they enable divers to interact with one another while underwater. Due to the challenging conditions of the aquatic environment and the limitations of verbal communication, divers rely on a combination of hand signals and light signals to convey essential information. This entry delves into the different types of diving signals, their history, and their significance in ensuring safe and enjoyable underwater experiences.

History of Diving Signals

The use of hand signals in underwater communication can be traced back to the early days of diving, when divers used rudimentary gestures to signal distress or communicate basic information. Over time, these signals have evolved into a standardized system, influenced by military, commercial, and recreational diving communities. The development of underwater torches and the growing popularity of night diving have further necessitated the incorporation of light signals in the divers’ communication repertoire.

Hand Signals

Hand signals are the primary mode of communication for scuba divers. They are simple, effective, and easily understood even by divers with limited experience. Hand signals can be classified into three main categories: general, safety, and procedural.

  1. General Signals: These are basic hand gestures used to convey common messages, such as ‘OK,’ ‘up,’ ‘down,’ ‘stop,’ and ‘look.’ For example, forming a circle with the thumb and index finger signifies ‘OK,’ while a flat hand with palm facing down indicates ‘stop.’
  2. Safety Signals: These signals communicate critical information related to a diver’s well-being and potential hazards. Examples include ‘out of air,’ ‘low on air,’ ‘problem,’ ’emergency ascent,’ and ‘share air.’ To signal ‘out of air,’ a diver makes a throat-cutting motion with a flat hand, while the ‘share air’ signal involves holding an open hand to the chest.
  3. Procedural Signals: These hand gestures pertain to specific actions or tasks that divers must perform during a dive, such as ‘equalize,’ ‘deploy surface marker buoy (SMB),’ or ‘check dive computer.’ To indicate the need to equalize, a diver pinches their nose and mimics the act of equalizing pressure in their ears.

It is crucial for divers to learn and practice these hand signals during their training and to review them regularly. The universal adoption of standard hand signals ensures that divers from different backgrounds can communicate effectively while underwater.

Light Signals

Light signals are particularly useful during night dives or in low-visibility conditions. They involve using a dive light or flashlight to convey messages by moving the light in specific patterns. Light signals can be divided into two main categories: general and distress.

  1. General Signals: General light signals mirror the hand signals used for basic communication. For instance, moving the light in a circle conveys ‘OK,’ while rapidly waving the light from side to side means ‘look.’
  2. Distress Signals: In emergency situations, divers use light signals to attract attention and seek help. Shining the light on and off rapidly or waving it frantically overhead signifies a diver in distress. It is essential to familiarize oneself with these signals to respond effectively in an emergency.

Limitations and Etiquette

While diving signals are a valuable tool for underwater communication, they have their limitations. Divers must maintain eye contact and ensure that their messages are acknowledged to avoid misunderstandings. Additionally, regional variations in hand signals may exist, so it is important to discuss and clarify any differences before diving with new partners.

Good diving etiquette involves using signals politely and not overusing them to prevent confusion. Divers should also be mindful of their surroundings, taking care not to damage marine life or coral while signaling.


Diving signals, both hand and

light-based, form an indispensable aspect of scuba diving communication. They enable divers to convey essential information, ensuring their safety and well-being throughout the dive. As diving continues to grow in popularity and attracts a diverse range of enthusiasts, the adoption and standardization of these signals become increasingly vital.

Technological advancements, such as dive computers and underwater communication devices, have enhanced divers’ ability to communicate while submerged. However, these innovations have not replaced the need for diving signals. Hand and light signals remain the most accessible and reliable form of communication for divers of all experience levels.

To promote safe and enjoyable diving experiences, divers must invest time in learning and mastering diving signals. They should also familiarize themselves with potential regional variations and practice good diving etiquette. Dive instructors, training organizations, and dive operators play a crucial role in reinforcing the importance of these signals and ensuring that they are consistently used across the diving community.

In conclusion, diving signals are a fundamental component of scuba diving communication. They serve as the primary means of conveying information and ensuring divers’ safety in the challenging underwater environment. As diving evolves and divers continue to explore the depths of the world’s oceans, the hand and light sign system remains an essential tool for fostering effective communication and fostering camaraderie among divers.