As is stated a number of times around this museum the Submarine Service was for many years the forgotten relation of the Navy whilst performing sterling work for UK defence. Starting with a tour around HMS Alliance a post war submarine in dry dock, you are guided through this vessel by veterans who actually spend time on these. You get a real taste of life on board and see the real mechanics of the submarine. After this went into the museums which covered from the very first submarine Holland I which is now kept in a controlled atmosphere through to the present day nuclear powered vessels. The place initially looked quite small but we ended up spending over four hours there. Only a small outside kiosk for food so if you do plan to eat here there are only minimal facilities. Plenty of free parking though so it's worth using this as a base and then getting the water taxi over to the main Dockyard in Portsmouth rather than paying high parking prices over there.