It can take less than 60 seconds for someone to drown if not rescued.
In this nerve-wracking video, a pool of busy swimmers all seem to be having a good time in the water.
But, amongst them, a little boy has lost control of his rubber ring and is struggling to keep afloat.
Not one of the other swimmers seems to notice the drowning boy’s flailing arms and attempts to grab attention.
But, thankfully, an eagle-eyed lifeguard was on duty.
Absolutely incredible.
The administrator of Lifeguard Rescue, who uploaded the video, explained that footage of incidents like this are posted to help raise awareness about the dangers in the water and to train other lifeguards.
They said: “I encourage you to use these videos as training tools to show new and returning guards what someone in distress or drowning looks like.
“I play these videos at trainings and go over common problems in our pools and similar traits our guests exhibit when they are in trouble in the water."
They added: “I also use them to have the guards tell me when they would go in for a rescue. I get some really great reactions.”
REMEMBER: Many victims of drowning are unable to shout or wave for help.
How quickly did you notice the little boy in distress? Let us know via the comments box below now.