A very interesting documentary, with reconstructed scenes, from the early days of cave diving and cave exploration... when fins and air were dangerous...
1st part https://www.youtube.com/watch?v=hYxMreI6BOU
2nd https://www.youtube.com/watch?v=bBw1pBfumIs
3rd https://www.youtube.com/watch?v=mSY2xe-YIl0
4th https://www.youtube.com/watch?v=HzgjgUl9GCE
1st part https://www.youtube.com/watch?v=hYxMreI6BOU
2nd https://www.youtube.com/watch?v=bBw1pBfumIs
3rd https://www.youtube.com/watch?v=mSY2xe-YIl0
4th https://www.youtube.com/watch?v=HzgjgUl9GCE