It is not in olivine it is in Kanto Region under lavender town were the bridge is u will see a house talk to guy there u have super rod.
no such thing not in soul silver
the fishing guru gives it to you in olivine city
The Fishing Guru in Olivine City gives it to you.
Saffron City
A house above the Pokecenter in Olivine City.
at olivine city
In Cinnawood City
olivine city
swim
In soul silver and heart gold you find it in euritik city in one of the houses
you do ecruteack city
It is in golden rod city