Willem Dafoe and Robert Pattinson stated that they barely spoke a word to each other on set and were too exhausted to hang out together after a day of shooting because filming was so physically demanding due to the miserable weather conditions. While Pattinson stayed at a normal hotel with the rest of the film crew during the shoot, Dafoe lived in a little fisherman's cottage in solitude. On set, on the other hand, Pattinson would tend to eat and stay by himself during filming breaks, while Dafoe stayed with the crew. Both stated that they liked each other very much as soon as they had their first real conversation a few months later.
The scene where Willem Dafoe's character gives the sea curse to Robert Pattinson's character because he doesn't like his cooked lobster was shot in one single take. According to director Robert Eggers, Dafoe didn't blink for over two minutes.
The dream sequence where Wake stands naked, beaming light from his eyes onto Howard, is a reference to the painting "Hypnosis" by German artist Sascha Schneider from 1904.
There were versions of the script that were "too clear". Director Robert Eggers's goal was to make the audience go mad and become confused like Winslow, so the final script turned out being more confusing for the audience.
Robert Pattinson's accent is based on a very specific area of Maine farming dialect, while Willem Dafoe's is the jargon of Atlantic fishermen and sailors of the time. Director/writer Robert Eggers was very precise about the actors' accents and line delivery. He would, for example, give instructions to "say the second sentence of your third line 75% faster."
Robert Pattinson: [Pattinson's character is sexually frustrated to the point where it leads to masturbation] This is the third movie starring Robert Pattinson in which his character has a masturbation scene, after Little Ashes (2008) and Damsel (2018).
Robert Eggers: [ominous-looking animals that haunt the main characters] The seagulls constantly haunt and intimidate Howard throughout the film. Similarly, in The Witch (2015), farm animals such as goats, chickens, and rabbits haunt and intimidate the family. In Nosferatu (2024), rats, dogs, and wolves haunt, intimidate, and attack several of the main characters and background characters during most of the film.
Robert Eggers: [folkloric, mythological, and fantastical period piece] The Witch (2015), this film, The Northman (2022), and Nosferatu (2024) are period pieces that are based on folklore, mythology, and fantasy which reflect through their atmospheres, settings, and environments.
Robert Eggers: [a character named Thomas] In this film, two of the main characters' names are Thomas Wake and Thomas Howard. In Eggers' first film, The Witch (2015), the main female character's name is Thomasin. The name Thomasin or Tomasin is the feminine version of the name Thomas. In Eggers' fourth film, Nosferatu (2024), one of the main characters' names is Thomas Hutter.