That particular room is probably on here somewhere, but it would only catch Sinclair's attention if there's literally nothing else on the map that would indicate a submarine dock. He's tuned in for something bigger than that.

"See these stairs here?" he touches the paper. "Those are the ones we just came up. So we're in this room right now," and again, "more specifically on this side of it."

And he wonders vaguely what Jack did learn back in Kansas. He can't be military, despite his skill in combat, for a multitude of reasons including the inability to read a map with any real efficiency. His skill in combat is what keeps Sinclair from thinking he was just a simple farm boy. That one's gonna eat at him until he finds out.