If you have ever been a diver of any kind this is a documentary you need to watch. I don't remember the last time a film hit me the way this hit me. If you've ever had an emergent or near emergent incident while diving, tending a line or being any part of a crew responsible for a divers life I suspect this will really hit home for you. This crew experienced the worst situation imaginable and put you in their shoes as they navigate their way through it.
I refuse to give you any spoilers.
This is the most you get. Just watch it.
https://www.imdb.com/title/tt9056818