The submarine, a massive metal structure that carries its crew into depths unknown, disappears without a trace from the surface. Immersion is imminent as I follow my captain through the corridors of his vessel: all around me are pipes and riveted plates, tubes, and vents. Time passes differently on this ship than it does elsewhere; only the captain has contact with the outside world when he sits at his periscope monitoring our route and destination. You are sitting in a conning tower, a small metal room that extends from the hull of your submarine. In front of you is an array of dials and switches, some for propulsion and others for navigation. The metallic ping of the sonar pulses in the glacial silence as it scans for any stray ships or icebergs lurking below you. The smell of diesel engines saturates the air, mixing with your sweat as it drips down from your forehead onto your uniformed shoulders. It’s hot inside this engine compartment, but not uncomfortably so! The noise is deafening hydraulics hiss as they move another piece of equipment into place; pipes clank loudly whenever someone moves; even breathing seems like too much exertion after being exposed to this level of decibels for so long (and yet everyone except you still seems comfortable). The metallic surfaces around you reflect light everywhere—both giving off light while also reflecting some back into your eyes through mirrors installed on strategic locations throughout each submersible unit’s construction process. Everything here has been made from metal: from weapons systems down through plumbing systems. It is a strange feeling to be able to see the world above while being at great depths below it. The surface of the ocean becomes a place that is both near and far away, and yet you are there. You could reach out your hand and touch it. But then again, perhaps not: the water pressure prevents any movement beyond what is necessary for survival. The lights are dimmed to a bare minimum because you don’t want to attract any attention from the enemy. You feel a chill run down your spine and wonder whether it’s due to being in such proximity with so many high voltage machines or if it’s just from the air conditioning system cutting on as they prepare for their mission (or perhaps both). It doesn’t matter though, because soon enough they’ll be gone off into the distance where no one will know what happens next until they return. Immersion is imminent. A submarine quietly folds into the unfathomable depths of the ocean, disappearing without a trace from the surface and taking with it a world whose space is enclosed in heat and wetness. The metallic ping of the sonar pulses in the glacial silence, and the smell of the diesel engines saturates the air. The heat is suffocating in the engine compartment, and the noise is deafening. Everything on the TIEFENMESSER is about metal, pressure and precision: the piping, the riveted plates, and the tubes. In the living quarters, time passes differently for the crew: monitoring their respective instruments (sonar or periscope) they are alone with their thoughts while one after another enters a trance-like state waiting for something that may never happen again—and if it does not happen today then maybe tomorrow. Except for the captain: monitoring the periscope, he is the only one to have contact with the outside world.