I was looking to carry on the tugboat theme this week with a suitable boat and digging through my Isle of Man archives, I found this one.
This is a tug, or perhaps more a pusher. It works with a dredging crane that lives on an unpowered pontoon. This unassuming vessel provides the grunt to move the outfit around. I'm guessing the big sign is to tell captains of visiting yachts not to tie up to the boat. Not that I think that many would want to attach their floating gin palace to a boat that is the very definition of "working".
Yes, this isn't a pretty boat, but I really fancy building a model one day. If I ever get back to the IOM, I'm going hunting for more photos.