That makes sense. [/sarcasm] Certainly World War II active sonar had no directional detection capability. It just bugs me how certain people think that not only should you operate with a paper bag over your head, but with earplugs as well for "100% realism." Hogwash.
You can install
TMOplot to get TMO's great plotting system that is as close to real as SH4 is capable of producing. It's not perfect, but it beats the paper bag and earplugs.