A drowning teenager was saved by a water lifesaving robot after being caught by undertow off the coast to Weihai of Shandong province on Tuesday, Qilu Evening News reported.

The local police remote controlled the robot and had it approach the struggling drowning swimmer who had been washed against the shore. The person seized the raft-shaped robot to float back to safety.

The public security authority of Weihai has introduced 74 water-based lifesaving robots since June to help fight the increasing emergencies inshore because of bad weather.

The robot is portable, fast in water, can sail for 30 minutes at most and can be controlled within 800 meters.