Gazza,
Not sure where you're from (NSW or otherwise) but the size is 50cms not 60cms there was no change to sizes restrictions so the old 50cms stands. This size is to small as many cod have not reached sexual maturity by this stage and have not spawned. If you want to refute my 50cms then please check your facts before making a fool of yourself by going S-I-X-T-Y 60 cms. Here is the NSW fisheries site to help you get a handle on the rules, lengths & bag limits.
http://www.fisheries.nsw.gov.au/recr...r/bag_fres.htm
As for letting 2 go, that would be great if all people were dilligent enough to check their lines every 20 minutes or so, but most people set their setties & leave them for hours & sometimes days at a time. The cod either die on the line or are so weak they die when released. Any way even if they are released with in an hour of hook up most cod on setlines are gut hooked. 10 minutes of pulling against the whipper snipper cord does immense damage to the fishes insides & the fish has less than a 50/50 chance of survival.
The just let it go answer is the legally right answer but morally it is not as far as I am concerned.
Just my opinion.
Steve