Is their another way to get Barboach in Pokemon sun and moon?

Question

I really want this Pokemon bad. I keep fishing but only come up wit magikarp.

Answer 1

Unfortunately the only way to get wild Barboach is by fishing.
However, Barboach encounter rates can be as high as 40% (compared to Magikarp's 50%), meaning it is not rare and you should be able to find one easily.

You can also obtain Barboach from breeding another Barboach or a Whiscash, or trading.

Note that if you are looking to evolve your Barboach into Whiscash, you can find Whiscash through SOS encounters from Barboach, skipping the needed level up(s) for it to evolve.

Answer 2

If you're fishing in Poni Gauntlet, Poni Meadow or B1F of Vast Poni Canyon, Barboach has a 40% chance of encounter through normal and special means so I don't know what's taking you so long.

If you're fishing in Paniola Town or Seaward Cave, Barboach has a 1% chance encounter so I assume that is where you're fishing. You should try fishing in the bubbling spots instead of just fishing normally; Barboach has a 50% chance of encounter in these bubbling spots so you should make an effort to fish in those spots instead.

Hope I helped. :)
Source