I don't get the hate for this movie. It's not cheap, it's deliberately small, focused and about as emotionally involved as you can get with a small crew of men acting in a 1940s way. I almost wish we hadn't had the bridge scenes with the command crew, and had to entirely take it from the point of view of the gun crew. That's how history happens; people go about their little part, and get these rare little views of the big action.
I was unusually not disturbed by the cookie cutter characters. We rarely see how they really are, but instead get their public face, to their crewmen while at war. People fall into bravado and storytelling just like this. There were moments of doubt and fear that showed this off I think, very well.
Stock footage, sure. But only rarely did I notice the grain mismatching, and they spent an awful lot of effort to make it blend into the narrative. My favorite of these is about 50 minutes in when one of the characters grabs onto a fitting on the gun to lean out and look at a heavily damaged passing ship. They did this because in the foreground of the stock footage is a sailor doing just that. It brought the stock into the story, and is such unseen stock of such specific damage you could never have simulated it with new footage, especially in the 50s.
I was especially pleased with the sets. I guess they are sets due to lighting and so on, but the interior of the gun mount looks absolutely perfect and realistic, and absolutely unexpectedly so. It really helped with the verisimilitude of the whole endeavor.