Here is the Bokalift 1 again. It was once a submersible heavy lift ship, but like one or two others has been fitted with a DP system and in this case a 3000 ton crane. So now it no longer submerges but is capable of maintaining station in the close proximity to a structure or a position allowing it to dismantle old platforms, install new ones, or in this case, position bits of wind farm structures. In August it was captured leaving Ijmuiden with a bit of a wind farm on the deck. This, since these craft are used more and more for wind farm jobs. There are a lot of them (Both the wind farms and the ships).
The photo was taken by Jan Plug, back in August this year and was posted here on 6th September 2020