Exactly, seems a bit late. Hasn't serious injury already occurred by the time a person is motionless on the bottom of the pool?

That'll teach me to pay more attention to the details rather than going "Welp, there goes my start-up idea".

Yes, that doesn't look great - I assumed when I saw it was underwater that it was effectively looking up at the people on the surface and detecting people in distress from that angle. On closer inspection that doesn't seem to be the case.