A team of University of Washington researchers developed AquaApp, the first mobile app for sending and receiving messages underwater that works on existing smartphones—no special hardware required. The app overcomes a number of technical challenges related to the underwater environment to enable two-way communication and networking while engaging in underwater activities like snorkeling and scuba diving. Credit: University of Washington
Key Points:
- AquaApp was developed by researchers at the University of Washington to allow divers to communicate underwater with their existing smartphones.
- Divers currently rely on hand signals to communicate, a technique that is often affected by less than ideal underwater conditions.
- The software solves many of the logistical challenges related to underwater communication by utilizing underwater acoustics.
A research team at the University of Washington has developed an app with the potential to make underwater exploration safer for divers. The culmination of the researchers’ efforts, AquaApp, relies on underwater acoustics to disseminate messages. Best of all, new hardware is not required, as the software can be used with smartphones and smartwatches currently on the market.
Underwater communication is vital to the safety of divers, who sometimes use over 200 hand signals to communicate life-saving information such as tank oxygen levels and the proximity of marine animals. The efficacy of hand signals, however, can be hampered by long distances and murky waters.
AquaApp presents a novel solution to underwater communication in those conditions. The University of Washington researchers describe their app in a paper they presented at SIGCOMM 2022, a conference dedicated to the advancement of communication networks.
"Smartphones rely on radio signals like WiFi and Bluetooth for wireless communication. Those don’t propagate well underwater, but acoustic signals do," said Tuochao Chen, one of the lead researchers. "With AquaApp, we demonstrate underwater messaging using the speaker and microphone widely available on smartphones and watches."
The developers achieved this by preloading into the app 240 messages commonly used by divers. Once a diver has selected one of the messages, AquaApp dispatches a notification signal—called a preamble—to the receiving device. That device, in turn, employs an algorithm to determine the best bitrate and acoustic frequencies with which to receive the message. Those frequencies are relayed back to the first device, and the message is finally sent utilizing those parameters.
"Based on our experiments, up to 30 meters is the ideal range for sending and receiving messages underwater, and 100 meters for transmitting SoS beacons," said Chen. "These capabilities should be sufficient for most recreational and professional scenarios."
The researchers liken the current state of underwater communication to the early days of the Internet, when access to it was restricted to a limited number of people. AquaApp runs on open-source code, and its developers chose a simple to download app with the intent to democratize underwater communication.