1 of 5Image
A pool-monitoring system in Wales on Aug. 28, 2005, spots a young girl sinking in the deep end. The Poseidon system, from Vision IQ, is designed to alert lifeguards in real time and give them the exact location of possible trouble.
At the bottom
Swimmers at the surface fail to notice the trouble below. And Vision IQ notes that it's "virtually impossible for lifeguards to see everything that is happening in the pool all of the time."