One of my favorite things about Iron Lung is something that a lot of people seem to have missed or written off: There's a medical, science-nonfiction explanation for Simon's hallucinations.
Many have complained that Simon's hallucinations are left unexplained. Some call it alien telepathic interference; others assume that Simon had a history of psychosis before the events of the film began. However, there's a perfectly pedestrian reason why our hero starts hallucinating and losing his grip on the passage of time, and it's telegraphed long before the first creepy flicker in the corner of his eye.
While the debrief plays over the radio, the Iron Lung is dropping to cruising depth at disconcerting speed. Simon is listening, but he's foggy, slow to react - You tested this thing, right? Why would there be flames? The hull? intact? Uhhhh looks okay to me (as plasma already congeals on the walls and wires).
As oxygen depletes, Simon's condition is compounded with hypoxia (chronic low oxygenation). He becomes more emotional, acts more erratically. After he's brought to the surface and argued with, he lashes out, and then is dropped to the ocean floor even faster than before. The narcosis hits him three times as hard. He forgets that crossed wires are more likely to short. He flails at the hull breach alarm, effectively destroying his radio. He decides to hold down the camera trigger with medical tape, which isn't designed to stick to anything but itself. He chugs a few ounces of precious water. He slams a double shot of rubbing alcohol, nstead of disinfecting his wounds with it. When he realizes he's been wasting oxygen talking to a hallucination, instead of shutting up to conserve energy he gets even more verbose and upset. As he takes one deadly radioactive photograph after another, his skin begins to blister and slough off. At one point he slurs, "You gotta get me out of here. I think I'm sick or something."
Simon flips through the submarine manual, scoffs at it, tosses it aside. He fidgets with frustration, curses sleepily, seems both agitated and bored. By the time he sees a shadowy figure cross in front of the camera button, he's sweating and shaky. Inability to process written information, cockiness, sleepiness, tremors, sweats - These are all symptoms of Nitrogen narcosis.
It's not just the eldritch fish monster that fried our convict hero's brain - although that certainly didn't make matters easier. The deep ocean can fuck up a perfectly functional brain all by itself.
Bravo, Mark and crew. Intentional or not, this film has so many layers.
