Three drug dealers set out on a voyage in a homemade submarine. The submarine works well initially, but it starts to malfunction. In an attempt to reduce the weight, the three men are investigating the cargo section when they discover a young female named Reina, who looks appalling. As the situation gets worse, the tensions among the three men escalate, and in the midst of this, Reina attempts to escape, but she has nowhere to go in the endless open sea. With an unusual setting of the submarine, where nothing can be seen other than the horizon, Submersible captures the tensions between the characters and their struggle for survival, while the submarine environment itself arouses extreme claustrophobia and anxiety. The top star from Columbia, Natalia Reyes, who attracted worldwide attention with Ciro Guerra's Birds of Passage (2018), once again draws attention in her role as Reina.