Part way thorough the flight of locks at Hatton, and handy for the excellent cafe, is this dry-dock for narrow boats.
The short arm can be dammed, and then drained to allow access to the bottom of the boat for barnacle scraping and re-blacking, both horrible jobs for the boat owner, or anyone they can pay to do the work!
Being outside, with no cover whatsoever, must limit the work that can be done. There's nothing in the way of fascilities either, so you take your wate from the canal (there is drinking water reaonably near) and electricity comes from a generator.
For modeller, there's potential here for a simple, and interesting addition to a canal scene.