BIG crowds, strong surf and powerful rip currents are only a few of the obstacles that lifeguards must overcome to keep swimmers safe. Strong winds can pull many bathers out to sea simultaneously, overwhelming the guards if there are only a few of them. And, since average swimming speed is about 3kph (2mph) even a single rescue mission can take more than half an hour.

A profession ripe, then, for automation. And that automation is now at hand. Hydronalix, a marine-robotics firm based, rather surprisingly, in landlocked Arizona, has come up with EMILY—the Emergency Integrated Lifesaving Lanyard. This device, which is being tested at Zuma beach in Malibu, California, is a remote-controlled, 1.4-metre-long, 11kg buoy with a foam core covered by red canvas and surrounded by ropes. A human lifeguard can keep but a single person afloat. EMILY, by contrast, is buoyant enough to save five at a time. The ropes let swimmers cling to the device or climb on top of it until a lifeguard arrives on the scene.

EMILY can be deployed from the shoreline, or tossed from a boat or aircraft. It is powered by an electric impeller of the kind used on jet skis, can travel 12 times as fast as a lifeguard, can make tight turns in choppy waters and can run for up to 130km on a single battery charge.

Hydronalix is already working on more advanced incarnations of EMILY. Next year’s model will have a Doppler sonar to help it avoid high-speed collisions with unsuspecting swimmers. It will also be able to seek out those in trouble, rather than relying on human spotters to guide it, for it will have sensors that listen for underwater movement characteristic of swimmers in distress. And it will be able to identify dangerous rip currents—powerful channels of water that are the cause of 80% of beach rescues.

The new version will also have a microphone and a loudspeaker. The mike will let EMILY’s human operator distinguish children splashing around from swimmers struggling for their lives. The loudspeaker will enable the operator to warn swimmers of danger zones, calm them down and instruct them how best to use EMILY. The only disadvantages, apart from the price tag of $3,500, are that swimmers who have been knocked unconscious cannot grab hold of the device’s ropes; and that, to be honest, it does not look quite as good as a “Baywatch” babe (or hunk) in a bathing suit.

Source: The Economist Online