Sunbury Lock Ait is a long island above the lock, separating the Left bank Lock Cut from the weir stream. The Right bank Sunbury Weir is above Sunbury Lock Ait. The weir stream continues on the right bank behind Wheatley's Ait and is joined by the River Ash.
Small boats could go more than a mile up this weir stream eventually reaching the Tumbling Bay at the head of Wheatley's Ait.

Middle Thames Yacht Club

Website. Access to the club is possible by club ferry from Sunbury or by using the club car park and a short walk on the Walton side.

1889: Jerome K Jerome -

We reached Sunbury Lock at half-past three. The river is sweetly pretty just there before you come to the gates, and the backwater is charming; but don't attempt to row up it. I tried to do so once. I was sculling, and asked the fellows who were steering if they thought it could be done, and they said, oh, yes, they thought so, if I pulled hard. We were just under the little foot-bridge that crosses it between the two weirs, when they said this, and I bent down over the sculls, and set myself up, and pulled. I pulled splendidly. I got well into a steady rhythmical swing. I put my arms, and my legs, and my back into it. I set myself a good, quick, dashing stroke, and worked in really grand style. My two friends said it was a pleasure to watch me. At the end of five minutes, I thought we ought to be pretty near the weir, and I looked up. We were under the bridge, in exactly the same spot that we were when I began, and there were those two idiots, injuring themselves by violent laughing. I had been grinding away like mad to keep that boat stuck still under that bridge. I let other people pull up backwaters against strong streams now.