Buoys still being buoys

It's hard to know where to begin with this one...

These are the same buoys previously pictured, but now they've been wrapped in these odd images. And I've no idea why. Perhaps I missed the very obvious clues (entirely possible), but I can't figure out what the whole thing is in aid of. 

I'm assuming it can't have been some grand, secret, underground art project, because it took two workman two days to complete the job, so someone would surely have challenged them if they weren't meant to be there.

But more importantly, it would probably have been a better job if it had been an underground project. The workmen took one day to do the first two buoys (left and right) and one day to do the third (the one at the back). And they made a right mess of all of them, getting steadily worse as they went on!

The buoys are covered in creases where they didn't smooth out the wrap properly, and they've left massive gaps on the last buoy. Now I admit it's probably not the easiest job in the world to wrap something buoy-shaped, but this is laughably bad. (Perhaps they should ask this accomplished blipper for wrapping hints?)

So, all in all, a bit strange. Have to admit, though, I rather like them...