In Mission Impossible: The Final Reckoning (2025), the noble gas mixture used in the dive suit is described as “classified”. This is because a real deep sea dive of this kind would use a helium mixture to prevent narcosis, giving Cruise a squeaky voice in a tense scene.

“Last Breath” (the drama, not the documentary) ignored the squeeky voice thing. I wish they would have at least acknowlaged it, and then went back to normal voices so it wasn’t distracting or goofy. Much like switching from russian to english in Red October.

Would it still give a squeaky voice at that pressure?