Canals are linear, shallow, and full of features people walk past: lock cuttings, turning bays, far-bank bushes, boats, and the track down the middle. Roach are the soul of it; perch, bream, carp and tench all show up.
You don't need a barrowful. A float rod or a short pole, maggots or punch, and quiet feet will outfish a feeder flung into the far bank. Watch for boats — they move fish, then the fish settle again. A Canal & River Trust water or a club stretch may need a permit on top of your rod licence.
Typical species
Roach, perch, bream, gudgeon, rudd, carp, tench, pike. Occasional chub on some urban stretches.
Tactics
Bread punch for winter roach. Maggot waggler or pole down the track and across. Perch in the lock mouth. Whip for a net of small fish. Don't ignore the near shelf when boats have pushed fish in.
Etiquette
Share the towpath. Don't block cyclists with a spread of kit. Net only what you need. Far-bank vegetation is someone else's cover — don't drag it out.
Close season & rules
Most canals have no coarse close season. Some canalised rivers and SSSIs do. If it looks like a river in a straight jacket, check before you fish in spring.