Made by Swedish startup Team Oceans, the wrist-worn S1 provides all the usual dive computer data – things like digital compass heading, elapsed time, current/maximum depth, water temperature, required surface interval before diving again, and so on. Information is displayed on a retina-class 2.2-inch color LED screen, and can be transferred via Bluetooth to an iOS/Android dive log app on the user's smartphone once they're out of the water. Additionally, though, if the user wants to get the attention of one or more other S1-using divers, they just tap a button on the device. This sends an ultrasound signal through the water (radio waves don't travel well underwater), which will be received by any paired S1s within a range of over 15 meters (45 ft).

Users of those devices will be alerted to the incoming "ping" via a haptic feedback system, that causes the computer to buzz their wrist. When they check the screen, a text message will tell them which diver sent it.

[Source: New Atlas. 7 February 2019. Ben Coxworth]