John, the Blackpool sub aqua club dived there in the 60s regularly along with most of the Lakes. You don’t forget your first dive even if it was 12 foot but I would have thought 15 plus back then. And salmon !! They were swimming so close to you.. I do have photos of going in but no underwater shots. I have an Elvis quiff in one shot. We even had to make our own wet suits back then !
I guess this is global warming, river management. Last time I visited, probably 5 years ago , I think it said, do not jump from the bridge or go in the water………it did look alarmingly low then.
Thankfully not lost my marbles yet but sad to hear it is so low a river at this beautiful spot.