For me the main attraction was the ships. They have the more than 200 year old flagship of Lord Nelson, "Victory" preserved and open for tours. This ship is up on the hard, and the top masts are down. She is a very well loved old lady. She is also still a serving warship as the admiral in charge of the Portsmouth navy base still has his office aboard.
There is quite a large collection of historic ships in the dockyard. When I was there the Mary Rose Museum was open for tours, showing the preserved starboard side of the Tudor battle ship "Mary Rose" and all of the guns, equipment and the remains of the crew that have been recovered. This ship was King Henry the eighth's flag ship he watched it sink in the Battle of the Solent just off Portsmouth harbour in 1545. Her starboard side survived buried in the mud with most of her equipment. The Mary Rose museum has been built around her and is designed to show her hull on one side of the viewing area and the equipment that would have been on that deck on the other.
There are still two more ships to talk about, so I'll continue in my next post