As folk who spend a lot of time in the water, we should be aware of other folk who might be getting into trouble - especially children. It's not all splashing and screaming:
http://www.slate.com/articles/healt...o_know_when_someone_is_in_trouble_in_the.html
http://www.slate.com/articles/healt...o_know_when_someone_is_in_trouble_in_the.html