Hi Simon,
If I remember corrrectly, that would be the terrain city, with the ships in the foreground!?
You could use that scene in an image of your own if you wish, although it would be expected that you would credit that aspect of it to me of course. Equally, you would not be allowed to use it in anything of a commercial nature. Personally, I would have thought that, given the tutorials explanation of how to create these terrains, and their source texture maps in Photoshop, it would be better to simply create your own version from scratch!? :)
Cheers
Adam