I have spent the day scrubbing the waterline and scraping barnacles off the bottom. The Coppercoat is very good, but a few barnacles do establish. Leaving them a few months to tackle seems to make them come of more easily. I presume the poor things are long dead. The antifoul boot top scrubs off quite cleanly with a plastic pan scouring pad. The problem is getting the paint either side clean enough for masking tape to stick to before I can repaint it. I have got one side half taped. I am going to widen the boot top considerably in the back half of the boat. The hull is nearly parallel with the water surface back there, and quite a bit of weed could grow on the paint surface above the boot top.
I have also carried the boot top round the bottom to the stainless steel rudder head, which does grow quite a bit of weed.