Premise: The Blackwater Lightship is a 2004 Hallmark Hall of Fame TV movie adaptation of the novel "The Blackwater Lightship" by Colm Tóibín. It aired on CBS on February 4, 2004. The movie stars Angela Lansbury, Gina McKee, Sam Robards, Dianne Wiest, and Keith McErlean. Lansbury received an Emmy nomination for it in 2004.
Hypothesis: The Blackwater Lightship aired on CBS sometime in 2004.