Article on what drowning really looks like/what to watch for, as opposed to the Hollywood version of thrashing and screaming for help.
Drowning Doesn’t Look Like Drowning
Article includes information on "The Instinctive Drowning Response – so named by Francesco A. Pia, Ph.D., is what people do to avoid actual or perceived suffocation in the water," which is so far from what people expect to see that "of the approximately 750 children who will drown next year, about 375 of them will do so within 25 yards of a parent or other adult. In ten percent of those drownings, the adult will actually watch them do it, having no idea it is happening (source: CDC)."
ETA: The first link doesn't seem to work for some people; the same information is mirrored here. (With thanks to dynapink and annoyedwabbit)