Whitewater... on the River Kennet?
The first is below the weir that exits the canal river right just before Newbury Lock, and which is accessed by paddling back up the channel that is to the left of the bottom of the lock when facing upstream after passing under Newbury Bridge.
The Kennet discharges from the canal to produce a small wave that can be side-surfed.
Alternatively, there is a sluice river left just under the A339 road bridge as you travel downstream. When sufficiently opened this can provide a more challenging wave.
The location of the sluice below the A339 road bridge. Access is from the left bank of the stream, behind the red brick wall in this image.
River left not only provides the easiest put-in, but also a large eddy.
The easiest approach to get over the side waves is from behind the concrete butress river left...
...but it's also possible to head in from the small eddy along the wall below the brick butress river right.
After that it's just a question of staying on, but there's only room for one...
...so for larger groups, Barbel Bar at Theale (or County Weir in Reading) might prove a better bet. It usually provides a consistent wave across it's c.15m length, although it was showing some variation yesterday.