Manufactured by Mercury Marine, the system incorporates wristband fobs worn by the captain and up to seven passengers, a central hub that's connected to the boat's propulsion system, and a mobile app.

If any of the passengers fall overboard, their fob transmits a distress signal to the hub as soon as it's immersed in the water. This in turn causes an alert to sound on both the hub and on all of the linked mobile devices, the latter also giving the GPS coordinates of the in-the-water passenger.

And should the captain fall overboard, not only will an alert be sounded, but the engine will also shut off. The app will additionally provide the passengers with instructions on how to restart the engine, then get to the captain's location. If they can't do so within a given amount of time, an alert will be transmitted to onshore emergency contacts.

1st Mate can also be set up as a theft deterrent system, in which the engine will remain locked until the captain's fob is within close proximity to the hub – or until the app is used to unlock it.

According to New Atlas