A "Wolf's Call' is a navy slang for active sonar alarm. That means the submarine is detected and targeted. Active sonars sound very different to the human ear based on the transmission frequency. Low-frequency sonars are a very deep, like a moaning bass. Medium frequency sonars are like some synth doing an imitation of whale songs. High frequency sonars are strident and creepy like "howlings."

ALFOST, the character played by Mathieu Kassovitz, is an acronym for "Amiral en charge de La Force Océanique et STratégique" (Admiral in charge of oceanic and strategic force), comparable to COMSUBFOR (Commandant, Submarine Force) in the US Navy.

The dog in Grandchamp's (Reda Kateb) home is his actual pet.

During a scene, Omar Sy can be seen driving a car with a small dinosaur toy placed on the dashboard. Sy also appears in Jurassic World (2015), which is a film about a dinosaur park.

One of Fourier's books can be seen in the bookshop's window display, right as Chanteraide arrives at the shop. It is titled "Optique de Fourier," and covers the study of classical optics using Fourier's transformations.