I used to dive but never went cave diving and not without good reason. As this documentary shows, its an extremely dangerous sport. You have to be a certain type of very calm person with nerves of steel and certain physical attributes, to pull it off. That said, as the team admit and sadly as this story shows, you may still meet your end.

The focus of this film is the story not the technicalities of diving. That said, when you see how deep these people go and the cave systems they navigate you can but be impressed by their courage and determination. Many of us would find the extreme depths, length of dive and the sense of claustrophobia, overwhelming.

In short, if you like diving this is really pretty addictive viewing. It has a simple style but really this is all that's needed. The story tells itself and shows not just how pursuit of a passion shapes us as people but also how friendships bind people together.

7/10.

We get to really experience something here. Friends who will go beyond anything one can imagine to recover the bodies of the people who have been lost. And the setup to the whole thing is important. You need to know what they are doing, and what they are letting themselves into. So while we still get maps and explanations during the movie, the beginning sets up something big.

Seeing the men (and woman) going underwater is incredible. It takes quite a toll on your body. But it also is exhausting ... so you can imagine how they feel. It's really draining and I don't think it will inspire too many people to do similar things. But it shows what people/human kind can achieve when there is a huge will and a force that drives you on ...

I enjoyed this documentary very much, but that was partly because I knew so much about the incident beforehand, having read about it in the news and diving forums. If I would have seen only the documentary, as a diver I would have wanted more details, technical data, analysis of the accident etc.

On the other hand, people who don't know diving terminology could find the lingo difficult to understand. Most used terms are not explained and neither are many of the reasons why cave diving in those depths is so dangerous. Maybe the English subtitles are easier to understand if diving slang is not used. Can't tell because I haven't seen those.

This is not a very detailed analysis of the events, but more a story about friendship and the psychological effects of the accident on the fellow divers.

The dead bodies can be seen briefly, but there are no close-ups which would make the footage graphic. In my opinion the most graphic parts of the documentary are the discussions held when planning for the recovery dive. What is the condition of the bodies, what equipment should be recovered etc.