Where do I start. Hellcats was the name for naval aircraft the F6F Grumman not submarines.They were Gatos. The submarine goes from a normal sized tube for a Gato class sub to a tube large enough to hold a 10' ceiling. Ronald Reagan's acting was as stiff as it gets. The dialog between him and Nancy Davis was as contrived as it gets. The dialog in general sounded like it was a Mark 7 production. There was a scene where a Japanese sub was firing its deck gun while the muzzle of the deck gun was still moving. Miraculous gunners they were because that shot and every other hit target. There were enrichment shots in the film that looked more like U boats than Gatos. The important thing is this movie ruined Ronald Reagan's film career. From this movie came TV and a B movie or two(made for big and little screens) and finally life in the desert as narrator of "Death Valley Days".