There is no such thing as a move called Swim. There is, however, a move called Surf, which is a HM, therefore impossible to get rid of, unless you use cheats.
A Magikarp, but I don't know if it is in the Johto region.
You need HM07 to teach your Pokemon the move "Waterfall" which allows he/she to swim up the obstacle to the other side. The HM can be found by talking to the man on the "Ice Path".
swim
by the end of new bark town and theres a lake swim in it and there is kanto falls but you have to have waterfall to climb it
Mantine is the Pokemon that uses the swim field move.
there isn't one, there is surf though
Go West of Olivine City where the Sea is, then just swim and follow the path really, it's not that difficult to find, (Cianwood City). Check it out on the map card.
Use cut or swim to the gym then once you enter it find the first button inside the bin and the next button should be right next to it
get the hidden move surf and swim about and you should find one
After defeating Misty in Blackthorn City, head back to New Bark Town and use your HM03 Surf to swim across (going east) to the Pokemon League. I will warn you now, this part of the game will not be easy.
Teach it the move Surf using HM3.
you get it from the elder in celestic town after you defeat Cyrus in the shrine