I served aboard USS ABRAHAM LINCOLN (CVN72) as a machist mate a-gang. The lower and lowest decks are where the machinery spaces are. Additonally, there are fuel tanks (aircraft need fuel, the propulsion systems are nuclear), water tanks, effluent tanks, and so on.
The fluids in these tanks are essential to the buoyancy and stability of the ship. The engineer’s world is something you won’t see on TV.
Most of those spaces require security clearances to enter and are very dangerous places to work. Maybe not as cinematic as launching an F-18 off the flight deck, there is absolutely nothing onboard any ship that would function without its engineers.
No catapaults or arresting wires, no water, no air conditioning or heat, no electricity, no propulsion, no steering, so on and so on.
