I just finished watching the first series on the sub. As a non-submariner (clearly), the technicalities are slightly (!) inaccurate but hey, it's telly and it was quite good fun for what it was; not a documentary. The problem is that even when we allow the TV folk in to produce a doc, we still hate the end result and we have endless threads as to the niagra of inaccuracies. Looking back, Fighter Pilot seems hugely professional compared to most of today's documentaries but we, as a military or ex military cohort are probably not the main target audience.
That said, there's no excuse for some of the actors' berets I've witnessed over the years.....