Scuba divers ordinarily use hand signals to communicate underwater but thanks to Casio Yamagata’s Logosease, now they can talk to each other almost as if they are walking on dry ground. All you need to do is face towards your fellow diver(s).
The Logosease modulates your voice into ultrasonic waves. You just tap once to start transmitting. Then you speak into the bone conduction microphone and tap to finish your transmission through the water. Your fellow diver then receives the ultrasonic waves and their Logosease unit will demodulate them via the speaker into an audible voice.
Typically if divers want to talk to each other they have to wear special face masks which are heavy and expensive. The Logosease, though, is affordable and easy to wear, and does not cover the whole face. Simply attach the device to your diving mask and you will be able to talk through the air regulator in your mouth.
The Logosease has a range from 50 to 100 meters (164-328 feet) and can function as far as 40 meters (131 feet) underwater. Of course, voice quality is not going to be as good as when speaking regularly on land but Casio still hails this as a world-first for an instrument of its kind.
It has also been approved recently as a distinctive specialty by the Professional Association of Diving Instructors (PADI) and promises to be an indispensable item for scuba divers around the world.