Oh My God !!! You saw what you wanted to see and were not prepared to accept you made a mistake. You have just lost all credibility hopefully in the eyes of more than just myself.
A BCU member has the right to paddle his canoe or kayak along the river. He has no right to fish.
Now it is your chance, you can have the same access as BCU members. Surely you do not expect it for free do you?
Go to the Canals and Rivers Trust and pay for a navigation licence.
http://www.nativewatercraft.com/boat_detail.cfm?id=48
But that will not give you any fishing rights.
Rivers Only £280.43 for boats under 18ft, but then if you have a boat you will already have that licence I am sure.