Crazy. I'm David Marquet, former nuclear submarine commander, and I'm gonna watch some submarine clips, and we're gonna rate them for realism. "The Hunt for Red October" (1990) Officer ...

And then, from under the ice, boom, a submarine comes up and starts chasing ... it can’t just look cool for cool’s sake, explaining: For movies, you always start with your character.

For his first command in the Pacific war a by-the-book officer is ordered to take his submarine on a reconnaissance mission to locate a fleet of Japanese fighting ships the Allies have lost track of.

However, things change when one the men is in a submarine trapped beneath the ocean and the other, a diver, is sent down on a rescue mission.