Dexter - Season 8, Episode 12: Soundtracks

Dexter chooses to mercifully shut off Debra's life-support. He carries his sister's sheathed body out to "The Slice of Life", upon which he drives the boat out to sea.

Dexter drops Debra's body into the water and drives his boat directly into the hurricane. Later, in Argentina, Hannah reads a report about Dexter's presumed fate.