Not sure that it blew minds that much as much of its core audience would have seen two great submarine movies - ‘The Enemy Below’ (1957) & ‘Run Silent, Run Deep’ (1958).
The episode takes and translates the submarine warfare and beats of these these movies into a space setting. It’s still marvellous television.
Recommend both of the movies BTW if you can find them.
Yeah, it translates them so closely that phasers act like depth charges and there's one part where both crews are trying to be quiet for some reason. It's a a brilliant episode, but that part was really jarring on my last rewatch with a friend.
God, yeah, it was an absolutely incredible episode. I watched it recently too, I was curious after seeing SNW's treatment of it. I never watched much TOS because it wasn't very engaging to me as a child in the 2000s, but I was drawn into BoT almost immediately and felt like I barely blinked the whole hour.