This is the Royal Navy Shipyard at Emerald Bay, featured in the Minecraft Airship Pirates Episode 5. In that video (the video linked on this creation) you get to see the shipyards bombed into oblivion by Silver Empire carrier based fighter craft.

I used QbicGaming's excellent "Old harbor spawn" for the basis of this build, adding fortifications, the shipyard itself, and the quad gun turrets. The quad gun turrets are fully functional, and are designed for AA defense. Also, unlike the original, this version will not burn itself down if you paste it into your world...

This also has a working main city gate with massive doors that swing open, demo'd in this video:
https://www.youtube.com/watch?v=YbOezZS06oU

And a working simple and elegant portcullis, demo'd here:
https://www.youtube.com/watch?v=jk3b204lKrY

In the shipyards are 2 Royal Navy Battleships (http://www.planetminecraft.com/project/royal-navy-battleship-airship/) and 2 Royal Navy Torpedo Corvettes (will upload soon). All are fully functional, although you would have to cut them loose from their harnesses to fly them.

Paste this standing on a block right at sea level. The city will appear all around you, you will be roughly at its center.

Notes:
To get Movecraft to operate the warships here, use this link:
http://www.planetminecraft.com/mod/movecraft-reloaded---loraxe42s-fork/

Use these craft files for Movecraft, put them in the plugins\\movecraft\\types directory:
https://dl.dropboxusercontent.com/u/11164014/MovecraftTypes.zip

Finally, if you need help setting up Movecraft, use this tutorial:
www.youtube.com/watch?v=hWHqnTkY330