That was part of what confused me my first time watching, and my only complaint about the film. They didn't do a great job of laying out the timeline of the original dive. In the original dive, where the two divers were lost, both groups left from the same location (the frozen lake), 2 or 3 hours apart. In the recovery dive, the two groups left from opposite ends, one from the lake and one from the cave.
Ty for clearing that up. I think i have to see it again sometime
