you use the good rod in a river or somewhere :/
Route 128 or Evergrande City (Super Rod)
you can catch corsola by fishing with a super rod in cianwood city while having the sinnoh music on.
You can only get a Corsola by trading it from Ruby, Sapphire, or Emerald. You can find Corsola in RSE by fishing in Route 128 (super rod), and by fishing at Ever Grande City (super rod)
supe rod
in front of the victory road there's a lake, you must use super rod to find corsola. then catch it wtih ultra ball
Go to Ever Grande City and either surf, dive, or use a Super Rod to get one. But be careful! Corsola's are tough to catch! :D
catch a wailmer with a super rod then level it to 40
you want catch it with the rod in rout 119.
Use super rod on the route by Evergreen City.
Use the Super Rod in Lilycove City.
I know in emerald you can at Mossdeep with a super rod.
To catch a Pokemon with a rod, you have to use the rod, then wait until a "!" appears above your character's head. Once that happens, press "a" as fast as you can before it gets away. If you land the Pokemon, you get to battle it.