I went to Chatham Dockyard (and the nearby city of Rochester) in June 2016. As Nan Mungard says, it's shockingly expensive, at £24! I had a National Art Pass, however, which allows free access.

The site is large and was very undervisited for a Saturday in June (hint to management: it might have something to do with the price). We enjoyed the submarine tour but the rest of the museum site verged on the dull. Huge buildings full of vehicles and model ships. A modern art gallery, some of which's works give the Saatchi Gallery a run for its money in terms of absurdity.

To be fair though I must withhold full judgement because I didn't go in the exciting-sounding "rope making experience" as several buildings closed an hour before the overall dockyard's closing time.