Its a tricky one indeed Mike, all I can suggest is a peice of guttering capped at one end with a measure glued in the bottom and maybe marked every 5cm with a marker pen so one can count the marks even from a full length photo. I would also suggest a three or four fish total length for the C&R prize, and if two anglers have exactly the same length over three of four fish then the one with the longest single fish out of the three or four wins. Maybe that will work, as the chances of two anglers having the same length in total and both their longest fish being exact are pretty steep odds. The guttering can be made by the angler or we can get some made with a £10 deposit from the anglers. Its a dick of a thing to have to carry around, but a couple of holes and a shoulder strap will make it easier, and after all if its all for the good of the bass then surely its a small price to pay.