From my memory of the place, it looks as if the pontoons shown in the picture are actually in the Great Harbour. The James Watt dock is the one in the foreground with the boats sailing about in it.
I have an interest in the place however in that it has been suggested as a possible place for the winter lay-up. It does not give a lot of confidence in the planners if they portray the development in the wrong place. Mind you, I was once at a presentation at which a bod from the MOD (Navy) was trying to convince us that it would be a great idea to build a base for nuclear subs on the Gareloch. As part of the presentation, he mentioned that it was only a couple of miles from the maintenance base (at Faslane) to the armaments store (at Coulport) and illustrated the short journey the subs would make to get from the one place to the other. "Just round the north of this headland" he said. This was questioned by one of the audience asking whether the boat would climb over Peaton hill or did they intend to tunnel through it? I would have thought that knowing the difference between sea and land would be the first requirement for a naval spokesman.