Intel
I had a presentation on the RN human intelligence specialisation the other week. It seems like a very good branch, as human intelligence all they do is focus on yes.... human information gathering.
basically, unless you have a strong foreign language (they will train you if you want) then you go down the interrogation route. If you have a language then you will go down the interpretur route. If deployed in sandy areas (very likely) then you will be conducting meetings with local people, in both overt and covert situations. Your not 007 and therefore have a undercover protection team for covert ops. Other roles include talking to skippers on routine boarding searches.
After gathering the information you pass it on to the analysts to do their stuff on it.
If you decide to go down this route then you can do your all arms commando course and act as an int officer on patrol with the royals.
This is what was made out from the presentation. This isn't a branch in itself its only a specialisation (human), but sounds better than studying photos and documents!