As Carlswark resurgence entrance is actually flowing at the moment, I thought it would be rude not go for a swim.
The entrance was snug and there was enough water flow to make entering a bit hard. Once inside I managed to turn round and swim. Vis was mostly poor and milky. I lost the way on and groped around for a bit trying to find a passage. Not sure how I did it, but found the stream again and I could actually see the floor.
I turned the dive at 29m in and set about removing the line and exiting in even worse visibility conditions.
“Bugger” I thought, as I went from drifting along winding up the dive line, to suddenly realising the gap in front of me was not big enough for me to fit through, “this is how people die”. The line had been pulled sideways, so I felt around and found a bigger bit of passage off to the left.
Had a few more problems getting out of the entrance as well. I followed the line up and felt vegetation but couldn’t get out. Shifted to the right a bit and wiggle tanks free before being blown out by the current.

Also managed to loose a dive knife, so if you go there when there is no water
1) I’d like it back if you find it.
2) Be careful that you don’t find it by crawling over it and stabbing yourself.