Memorial Day weekend 2024 started with a blue sky and a mild three- to four-foot chop in the water off the Gulf Coast of Mississippi — a perfect day for a fishing competition. A team of five was about 40 miles offshore checking their sonar, and 30 seconds later the boat was gone. They were in the water struggling to pull on life jackets and grab the coolers as they bobbed up. When a boat sinks, survivors can be virtually invisible amid the vast expanse of water.

When their fishing trip went wrong, Easton Barrett had the only mobile phone and no cell service. He recorded a brief farewell, planning to put his phone in a cooler in hopes someone would find it.

Another team member activated a personal locator beacon (PLB) that had been stowed at the last minute, which sent a distress signal to the Search and Rescue Satellite-Aided Tracking (SARSAT) technology carried by multiple satellites in Earth orbit. In the SARSAT system, developed partly by NASA, an emergency signal containing the transmitter’s location is directed to the nearest available ground station.

A mission control center then alerts rescue coordination centers to mobilize search and rescue crews. For Barrett and his crew, that was a Florida Coast Guard boat.