Distressed swimmer or drowning non-swimmer (DNS) is a term used by the Life Saving Society of Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 to describe a particular victim type.

Lifesaving Society Definition

Distressed swimmers can be novice swimmers with limited swimming ability, tired or weak swimmers, and people who are ill or injured. This group also includes swimmers who become disoriented after playing in or falling into the water. Unless they are rescued, distressed swimmers can become drowning

Drowning

Drowning is death from asphyxia due to suffocation caused by water entering the lungs and preventing the absorption of oxygen leading to cerebral hypoxia....

 victims.

Usage

The acronym "DNS" is a commonly used term within the Canadian Lifesaving Society to expedite the process of describing a victim. This is particularly useful in emergency situations where time is of the essence, and where the phrase "drowning non-swimmer" would be difficult to say.