In the '90s I visited a younger cousin in South Korea. Military service is mandatory there, and he was enlisted in the Navy. He had the craziest haircut I'd ever seen—completely shaved around the side, but with absurdly long bangs, like a front-mounted topknot. I asked him what that was about, and was stunned at the answer: "They can use it to pull you out of the water."

I found that crazy—and creative. A brutal piece of UX, essentially adding a design feature to sailors.

A company called Float Buddy does something similar for smartphones. Their eponymous product, designed for Boat Life people with butterfingers, is a clunky-looking device that attaches to your phone via a mounting disc that you permanently adhere to your phone's case.

If you drop your phone into the drink, a water-sensitive trigger inflates a red buoy, allowing you to locate and grab it.

Downside: The $60 device is, like an airbag, single-use.