Apple is investigating whether its watch can prevent drownings.

An engineer with Apple has proposed an innovative system for an Apple watch that would detect if a swimmer is getting into trouble.

The company filed a patent for its invention, called a “Wearable Device Used as Digital Pool Attendant” this March. The patent proposes to determine whether a user is swimming or not swimming and whether the user is showing regular or irregular behavior while swimming. Based on this sensory data, the watch would send an alert message to one or more nearby Apple devices. “Examples of use cases include, but are not limited to, sending an alarm message to nearby devices when a non-swimmer or small child unknowingly enters a deeper area of a swimming pool; sudden fatigue of a swimmer due to specific health issues; or heart attack of a swimmer during a swim,” the company states in its patent.

The device would detect the relative positions of the swimmer's legs, torso, head, and arms, and could detect irregular behavior associated with a swimmer in distress or a swimmer who is unconscious. In addition to position sensors on the smartwatch, a heart rate sensor would measure the swimmer's heart rate, which may suddenly elevate when the swimmer is in a panic, or if their blood oxygen level suddenly drops because the swimmer cannot breathe.

The Apple Watch has already saved lives. Some users have been notified of their dangerous health conditions in time to seek help. Others have used their devices to call 911 when they’ve gotten in trouble.

But this is a little different. For the Apple Watch to act as a swimming pool lifeguard, it would need a method to put the wearer in contact with nearby iPhones so that they could receive a distress message.

While the patent application doesn’t guarantee that the idea will become a reality, the company is working on Apple Watch OS 11. The lifeguard watch is a very real possibility.