This movie was made in 1971. There was no talk about great white sharks, or sharks for that matter. I saw this in the movie theater and the last 10 minutes when they finally find the great white shark is exciting. Of course, tons of studies have now been done about the great white and this movie is out dated. But the most important information in the movie was that the crew had absolutely no knowledge where to look for great whites and that is why the movie took so long to find one. And the cage scene is real, the shark did get his fin caught and the pressure of him trying to get out of the bars bent the titanium metal. That's power. Members of the crew and the cage was brought to the Johnny Carson show and it have great exposure, so did Spielberg get his idea for his movie from this 1st movie, who knows?