Yamagata Casio have come up with this brilliant way for divers to communicate. The Casio Logosease is the world’s first two-way underwater radio walkie-talkie device. With a range from 50 to 100 meters (164-328 feet) and the ability to work at depths of 40 meters (131 feet) under the waves, you just have to face each other to speak to your fellow diver.
But radio waves do not travel underwater. How can you talk to another diver? By ultrasonic waves. Well, the unit modulates voices into ultrasonic waves. Simply attach the device to your diving mask and you will be able to converse via an air regulator in your mouth.
Tap once to start transmitting and then tap again when you are finished. Your partner(s) will then receive your audio as modulated ultrasound which is demodulated via a bone conduction speaker. While the voice and audio quality is not as perfect as on land, it is still clear enough to enable safe communication.
Underwater two-way radio (LGS-RG 005BA) by Yamagata Casio
Two units per set
Microphone: bone conduction microphone
Speaker: Magnetic-type bone conduction speaker
Size: 89 x 41 x 44.8mm (3.5 x 1.6 x 1.8″) (each)
Weight: around 107g (3.8 oz) (each)
Usage temperature: 0°C-40°C (32°F-104°F)
Ultrasound: 1 channel 32KHz USB, 4KHz SSB-AM basis
Power lasts for up to 3-hour dive (if used around 10% of time for transmitting)
Works up to 40 meters (131 ft) underwater
Range: 50-100m (164-328ft)
Voice is quieter with distance
Divers must be facing each other
Power: 560mAh Li-ion battery, charge by USB
Charging: around 2 hours
Instructions: Japanese (but Casio Yamagata has FAQ and other information online in English)
In Japanese waters there are no restrictions on using ultrasound but please check laws in other countries before using