Researchers in Okinawa Japan have developed a communication system which uses LED lights as a medium for underwater communication. The device works by first taking sound and converting it into a light signal. The LED light will then transmit the signal to the other person’s receiver where it is reverted back to sound.
The majority of underwater communication is through costly ultrasonic receptors. Therefore many divers instead use hand gestures to communicate back and forth, though this is limited in the information that can be conveyed. For beginner divers who are not yet quite familiar with all the gestures, this form of communication can lead to problems in emergency situations.
The LED underwater communication system was originally only able to send signals from a distance of 1 meter, but now divers are able to converse within 30 meters of one another. The device can be battery powered for up to 4 hours. It is also not constrained only to communication between divers underwater, but can also send signals to someone on land from underwater. There currently are plans to minimize the size of the device in the future.