The Locks on the Avon @ Keynsham.

I was sat on the Lock gates @ Keynsham,near where I live.Just looking for a nice river scene for my Blip.When a Narrow Boat enters the lock so as to assend to the lower River Avon.
The exit lock was opened to take the water level to that of the river.The swirl of the water was quite powerful and created quite an undertow so I dropped the shutter speed on my D3 fitted with my Nikon 24-48 ED VR lens,to 1/10 sec @ f11 iso 200.Giving the movement in the water so often seen in waterfalls rather than river/canals?
Hand held by the way!My nerves must be getting better?
And yes it is that town spelled K-E-Y-N-S-H-A-M for those old enough to remember? lol