We had shower curtains in the heads, so it wasn't too bad. Then they added women onboard and things got changed, a lot.
We had stainless steel phone booths, with doors. If you were claustro you were out of luck. But you wouldn't have been on a sub anyway I guess.
Sounds about like what we had on the Charlie Deuce... but, no doors.
The doors were very solid, about an inch thick and full of insulation. Door handles and brass latches. There was an air grille about four inches square with louvers at neck level (Well, my neck.) You needed to crouch down to try to peek out before emerging else you could really de-nut a shipmate who wasn't alert. All the heads had the same design: crew, goats, officers, and CO/XO. I think it was so the heads could be very small footprints and still no splashes escaping on guys at the sinks.
When some guy went Hollywood and the COB caught him there would be a metal bar impacting the shower booth. Like being inside a bell. (Not when we were alert or mod-alert though. Then the offender got TDU-duty or "s**thouse mouse" rotations. Those might be sub-only things.)