Well, rather meager details, but:
https://en.wikipedia.org/wiki/Fleet_Radio_Unit
https://en.wikipedia.org/wiki/Station_HYPO
The main station in Washington DC had a moniker like Hypo and Cast, but I cannot recall it... Wacky??... Anyway, early in the war, there weren't so many of the Ultra messages, but they did steadily increase in frequency, and their accuracy improved also, as they got better at decyphering IJN transmissions. The information was then sent via nightly encrypted messages, addressed to specific submarines, and was a closely guarded secret. If I understand a book I have correctly, even the radioman didn't know how to decypher them, only the Captain and a few other officers. No mention was made of the system outside the ONI until well after the war. So getting the reports is something I would consider very "realistic" in the game, though they are done a bit over-the-top.
I was writiing a script using Notepad++, meant to run through all of the 4Xx_Jap_* mis files I was experimenting with changing every fifth or sixth group. However, I never did figure out a way for it to NOT report the "DockedShip=true" RGG... I'll try to get further into that for FotRSU later. What I would like to be able to do is have the game specifically address the player's sub, based upon their location, and give them a message to be at a specific location at a specific time & date to intercept a given convoy, or submarine, that is actually part of the game, and have the player be close to where the units pass... but my idea involves the little-known-or-understood "DynamicMiss.cfg" file, and my experiments with it are in the very early stages. I might die before I finish with it...
- and there's 20 other things in line ahead of that...
