How should emergency signals be communicated underwater?

Communicating emergency signals underwater is crucial for safety and efficiency, and using hand signals or underwater communication devices is the most effective method. Hand signals are widely recognized among divers, and they allow for clear and immediate communication without the need for any additional equipment, making them ideal for emergencies when time is of the essence.

Underwater communication devices, such as underwater radios or communication harnesses, further enhance this capability by allowing divers to communicate verbally without breaking the surface. These methods are designed specifically for the underwater environment, where vocal communication is not possible due to the density of water and the need for breath control while diving.

Other options, like shouting or using written notes, are impractical in an underwater setting. Shouting is ineffective since sound travels differently in water compared to air, and it is impossible to hear clearly. Written notes would require holding a piece of paper, which is not feasible underwater and would also take time to read and respond, potentially delaying critical communication in emergencies. Light signals, while useful, are limited in their range and effectiveness, especially in murky water or when visibility is low, making them less reliable than direct hand signals or communication devices.