The "Estuary Victim" is a character seen in the film Jaws which is a dramatic chronicle of the infamous "Amity Incident" which was released in 1975.
In the film Jaws, a local boy scout leader is asking Michael Brody and his friends how they are doing, when a rogue, 25-foot Great White Shark comes and knocks him off his boat. The shark then proceeds to tear him apart and devour him. His leg is seen sinking to the bottom of an estuary also described in the film as "The pond".
In the real life version of the incident, the boat was a brown canoe. The use of red in the film was made as a specific choice by director Steven Spielberg in order to highlight the drama and fear projected to the audience. To this day, fans of the film consider this the benchmark scene in the film thought to be responsible for keeping bathers out of the water for many years following the films release.