I posted this link a year or two ago but can't find my original post on here to bump, so a new thread it is.
slate.com/technology/2013/06/rescuing-drowning-children-how-to-know-when-someone-is-in-trouble-in-the-water.html
Drowning can be a deceptively quiet event, nothing at all like the wild thrashing and yelling depicted in TV shows or films. This article tells you what to look for - if someone isn't moving much, very quiet and unable to respond, get them out quickly or call for help.
Jo "Safety enthusiast" Brodie :)