The big big holes happened when the two divers found the gold and the drive shaft inside the derelict German submarine. Pulling and removing a drive shaft would have been a pretty big job if they had just had that to do, but they chose to deal with it by not bothering to show how they were supposed to do it and instead giving the impression it was such an easy job, it wasn't worth even showing it - hey, they found it and now they see it, now it's done! And the other big hole was all that gold they found within that submarine weighing two tons! Again, it would have been a pretty big job just moving all that gold to where they would be able to get it through the submarine beside the same place and way they got into the submarine to begin with - beside the pressure lock obviously. And there, they would have had to hand carry bars of gold into the pressure lock, fill it with seawater, carry the bars and then place them onto some cart which appears out of nowhere somewhere outside the submarine onto the seabed floor. It would have taken a whole lot of work, a lot of time, maybe a few days and a lot of trips with all those bars weighing a total of two tons! Where did they get all that oxygen? And then they would have - or rather the eighteen year old kid would have had a lot of work on his hands getting the gold into the salvage submarine, because the other guy was killed when he fell off the edge into a deep canyon. And the kid was not portrayed as much an expert diver to begin with. And where did that winch come from? If any of this was possible, before even attempting what they were planning to do, there would have been a scene where a few of them stand over a table making sketches and calculations about how they were going to even attempt a big job like this. But I suspect the makers of this movie nixed such a scene as that because of the impossibility of such a job to begin with and decided to just leave it up the viewers imagination which is the only way to do such a job as that - in one's imagination. But the movie was entertaining even though it lacked credibility.
