Main Ventilation Shaft Section C is part of a network of ventilation shafts in the Frigate Orpheon in Metroid Prime that Samus travels through after the Parasite Queen battle in order to escape the frigate. This section contains a swarm of Parasites that are most easily avoided using Morph Ball.
This room remained intact after the Orpheon crashed into the Tallon Overworld. Rock formations broke through part of the shaft, and function to provide steps for Samus. The bottom of the shaft is flooded, and the huge rock at the bottom is blocking the door to Main Ventilation Shaft Section D. Access to that room is not possible after the crash. An Aqua Sac is visible beneath the glass floor. The water contains a school of 5 Fish. There is a passage leading out of the water that contains some debris that must be circumnavigated using the Morph Ball.
- Main Ventilation Shaft Section B (via Blue Door before and after crash)
- Main Ventilation Shaft Section D (via Blue Door) (Before crash)
- Frigate Access Tunnel (via Blue Door) (After crash)
- The Crash-Ship-MAE theme plays in this room after the frigate crash.