If you have RA, I believe it comes with an Excel spreadsheet of sonar frequency values. Often, the sonar values are as/more important than the visual makeup of a ship, I think.
If you wanted a 'visual recognition guide', there are a few good places on the net - the CIA's Freedom of Information Page, old computer game manuals (like
Red Storm Rising)
Check out Annex B of this doc:
https://www.cia.gov/library/readingr...ent/0005512850
Or this:
https://www.eugeneleeslover.com/US-N...-B-PAGE-1.html
That helps me most of the time. If I need more technical information, say, about a torpedo coming at me, it only takes a few seconds to check the UNSI database.
Just my 2c,
Stew