Re: Catching Feebas
Feebas is available in a certain block of six squares in the route 119 area south of Foretree city, which changes every time you change the trendy phrase in Dewford. I have NO idea what the bloody hell a trendy phrase in Dewford is, and none of the pages in google results are explaining so sorry. There is no way of knowing however where the six squares change to exactly, you just need to fish around.
Since I did not understand the method, I in my sapphire simply just randomly fished around until it showed up and caught two to trade one to my bestie's Ruby(once you find one, the square in which you found it produces them like magikarp).
Took me a second try to evolve it however, as I had reached pokeblock feeding maximum before it had reached maximum beauty, but I just had to breed for a new one. Feebas can breed with Magikarp so once you capture a female feebas you never have to waste your time fishing around again.