Drowning is almost always a deceptively quiet event. The waving, splashing, and yelling that dramatic conditioning (television) prepares us to look for, is rarely seen in real life. This doesn’t mean that a person that is yelling for help and thrashing isn’t in real trouble – they are experiencing aquatic distress. Not always present before the instinctive drowning response, aquatic distress doesn’t last long – but unlike true drowning, these victims can still assist in their own rescue. They can grab lifelines, throw rings, etc.

http://mariovittone.com/2010/05/154/