Some Help, Please!

Two grandogs on an sleepover. Two enthusiastic Springer Spaniels. Up, feed dogs, out for a quick 20 minutes. Later out for longer walk through Colinton Dell which is great for blips in the Summer but less so in winter. . Weather dank and hanging - moisture in the air but no rain. Grey and dull. However, a good day to try camera experiments. I stayed with Manual and decided to try for silky water at a weir. I took a fair number of shots varying ISO and shutter speed. I decided to make no processing changes and would welcome advice on how to improve this shot.