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 Winslow, is a reference to the painting "Hypnosis" by German artist Sascha Schneider from 1904.
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."
The film was shot on Double-X stock black and white, which requires much more light to get exposure, so when they shot at night and indoors, they had to use about 15 to 20 times more light on set to actually see something on film. The crew put flickering 500- to 800-watt halogen bulbs in period-correct kerosene lamps that were only a few feet away from the actors' faces, resulting in the set being blindingly bright and the actors barely seeing each other. The lights were so bright that crew members sometimes wore sunglasses even during night shoots.
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 main characters.