Kursk was a bit of a disappointment. A submarine control room as the setting of a play isn't a bad idea - the movies worked that out many years ago - and putting it on as promenade theatre through the simulated sub is a cracking one. But, not quite.
It did remind me to check the (excellent) Wikipedia article on the loss of the Kursk, which answered my question. The problem is that the story doesn't really provide for a good drama from the viewpoint of a British submarine; even if you accept they were present, had they decided to surface at once and steam up to the Pyotr Veliky, the best thing that could have happened would have been to launch the ineffectual Russian rescue attempt a few hours earlier, which would have changed nothing. Most of the dead were dead within seconds; the survivors survived for days, almost long enough for the eventual British and Norwegian rescue effort to save them.
This leaves the story as a pure sea-piece; the isolation of the submarine, the role of the captain, the character conflicts, navy culture, the details of control-room procedure. In fact, the set's two-level structure, laid out around the central search periscope, isn't all that far off the Navy's original submarine simulator in design. In the original, the mockup control room was on the lower level, with the periscope rising through the ceiling into a room where the images required for the training scenarios were projected onto the walls.
You could make a case for secrecy being the main theme, but again, it doesn't quite work. A minor note is that there's a fair bit of Americo-scepticism about; the presence of two Los Angeles-class boats in the area is pointedly briefed as the American "threat".
Seen as science-fiction, though, it holds up better. An SF writer, whose name I forget, once said that there weren't any wars in his books because the universe was enemy enough.