With the talents of a clever friend, some hard work and a few extra bits of wood, fabric and plastic, it now looks like this...
Three walls were great, so they were re-used with fence posts to help stabilise. The roof was remade with a wooden frame and corrugated plastic. the floor was decking boards upside down so there were no ridges under bare feet. There's sailcloth tied to hooks on the ceiling to stop the sun making it too hot from above.
At the moment there's a writing desk although, as winter dampness encroaches, it will probably move indoors.
This is the view down the garden while writing.
Various ship/ piratey stuff helps make it feel like a cross between a stage, a raft and a cabin. Perfect.
The outside is painted pale blue, as you have seen on a previous blog (http://socklet-world.blogspot.co.uk/2016/06/revolution-in-garden.html), and see through plastic tablecloth roll winds up and down at the front to keep it cool/ warm as needed but still lets you see the garden an feel outdoors, even in the rain. Velcro keeps the cats out.
And in the dark, the back of it looks like this...
Here's what Prisma says about it
It could definitely float away, like the stage in the Moomin book, Moominsummer madness.