When I was a lad and satellite navigation was a dream, nautical navigation relied a lot more on things like lighthouses. Lightships were a big part of this, and Trinity House had a number of them stationed around the UK coastline. One was at Calshot Spit in the Solent and so I would see it every time I looked out of the window of our flat (and also when crossing on the ferry). I guess these vessels became surplus to requirements over time and got taken out of service. Apparently, the Calshot Spit vessel was moved into a development in Southampton but, again, became surplus to needs. Fortunately, it has been saved and is currently alongside the Solent Sky Museum. It isn’t open to explore but sits alongside the road. I assume there is some restoration work required.