This is another of my favourite watercolourists:
John Knapp-Fischer, who painted mostly in Wales but also in the Cape (South Africa). I use his work often to demonstrate the importance of tone in the composition and drama of a work.
I had the chance to buy a triptych of his small sketches in Cape Town years ago but didn't, and have been regretting it ever since. Now when I am drawn to a piece of work, if I have the money, I buy it.