Prawns are the bait I reach for when a swim has gone dead. Not because they are magic, but because they are completely different to whatever the fish have been seeing, and on pressured water difference is the whole point.
Why they work
Most coarse fish in Britain encounter maggots, worms, corn, pellets and boilies constantly. On a busy fishery they see those baits every day of the season, and the better fish learn to associate them with being caught.
A prawn is outside that set. It is high in protein, it smells strongly, it is tough enough to stay on the hook, and it is large enough to select for better fish. It is also visually distinctive, which matters in clear water.
What to buy
Plain cooked prawns from a supermarket. Not marinated, not garlic, not dressed in anything. The cheapest bag of plain cooked prawns on the shelf is exactly right.
Frozen is fine and arguably better, because you can take out what you need and refreeze the rest rather than throwing away a bag every session.
Some anglers swear by dyeing them red or flavouring them further. I have never found it necessary.
Species by species
Perch are the classic target. A whole prawn on a size 6 fished hard on the bottom near structure is a proper big-perch bait and filters out the small ones almost entirely. See best baits for perch.
Chub take prawns readily, particularly in clear water where they have seen a lot of bread and meat. Fished under a bush on a light link, as you would a slug or a lump of flake.
Barbel respond well to prawns in summer, and they survive the current better than meat does.
Carp will take a prawn, and on waters where the carp have become boilie-shy it is a legitimate change bait rather than a novelty. Two prawns on a hair is a big, obvious mouthful.
How to hook them
Through the tail end, once, leaving the body free. Or on a hair rig with a small band or a bait floss whipping, which keeps the hook completely clear and works better for carp and barbel.
Prawns are tougher than they look but they will fly off on a hard cast if the hook hold is marginal. If you are casting any distance, use the hair and floss method rather than trusting the hook.
Feeding
Chop a few and introduce them with whatever else you are feeding. A handful of chopped prawn in a swim is enough to get the scent working without filling fish up.
Do not overdo it. This is a bait that works partly through novelty, and a swim carpeted in prawn stops being novel.
Practical notes
Keep them cool. A bag of prawns left in the sun for six hours is unpleasant for everyone including you.
Take the leftovers home. Prawns are not a bait to tip in at the end of the session, and the smell in a car boot two days later is a lesson you only need once.
Check fishery rules. A small number of commercial fisheries restrict certain baits, and it is easier to ask than to be asked to stop.

Dan Whitfield started fishing aged seven on the canal at the end of his road and never really stopped. He spent his twenties and thirties on the match circuit – club level rather than national – before deciding he’d rather catch one decent fish than a net of small ones.
These days he mostly fishes the River Trent for barbel (personal best 14lb 2oz), the Oxford Canal for roach and skimmers in winter, and the occasional gravel pit when tench are spawning and the surface fishing is too good to miss. He’s a former club secretary and still helps with junior coaching at his local angling club in Nottingham.
At The River Bend, Dan writes the coarse species guides, river fishing technique articles, and the match and pole content.
Covers: Barbel, bream, roach, tench, carp (coarse context), river fishing, canal fishing, feeder, float, match/pole