First tip in locating barbel in a river like the Trent where you can't see them is to find a good gravel bottom, preferably also a swim on the outside of a bend.
Barbel love gravel, as they often feed by sucking in the pebbles to get numerours forms of food off them and then blowing them out. They also dig deep into gravel after all sorts of living matter. Barbel will show themselves on the surface from time to time. They come up with a head and tail rise like a dolphin.
Once you have found your barbel, get some bait going in. This you can do with a bait dropper or with a heavy feeder by casting out and jerking the bait off.
One of the best barbel baits are pellets in various forms. Fishy marine halibut pellets are almost an instant barbel bait these days. Use a small 3mm pellet to bait up and a 13mm pellet or even two of them hair rigged on a simple link leger set up that will just hold bottom. You can also use a feeder.
Don't concern yourself with complicated hook lengths or rigs. Use a fairly long fluorocarbon hooklength of 8 lbs to 10lbs bs with a 12lb main line. Hook sizes: 10 to 6, depending on the bait size.
PVA bags attached to the hook full of freebies are also a deadly way of attracting barbel to your bait.
But I will repeat, succesful barbel fishing is all about locating them. You will find that once you have found them, they are not hard to catch, especially if you fish into the evening.
And if you suddenly find your river in a summer or autumn flood, get out there; these are the best conditions of all. Fish under your own bank, over gravel and when the river is in a really heavy flood, try a big lump of luncheon meat.
