I cant quite believe that you blart on about the supervision of nets then show this photo?! I personally would not have opened up in those conditions, the net looks like its been left for a while? and it's as slack as a bag of Knacks. I used to operate on a huge private ringing site with 15 - 20 nets open in a range of habitats. What is your definition of Supervision? I thought 'the manual' says nets sould be checked within 40 minutes (?)of each net round (i cant be bothered to go upstairs to check the manual) The witch on the horse had a pair of Scissors to cut the birds out (all small stuff, tits etc and probably only 8-10 birds, 20 was an exhageration!). We did a net round (5 nets up in a strip of mixed woodland THAT WAS PRIVATE) that took about ten minutes, then two took the birds back to the ringing hut and the other two went back to the first net, where the girl had cut out the birds. Thats plenty of time to cut birds out. You could extract 8-10 birds in 10 minutes, never mind cut them out!
Bird Obs (take Spurn point for instance) have nets spread over wide areas. I wouldnt say they were 'supervised at all times'. They are checked on a regular basis, as are mine, but are not supervised at all times?
Anyway, like you say, i dont want to get into a slagging match. Ive bin ringing for 18 years and dont need you to tell me when its time to check the nets, but thanks for your input.