Who is a good counter for water types in SUMO?

Question

I don't know who to train

Answer 1

This is a pretty vague question, so I'll try my best to help

Here's a list of the entire Alolan Pokedex, meaning you can scroll through and pick out the Pokemon you think would be best for you.
If you're looking for a good counter from the very beginning, here's the Melemele Pokedex. Strictly speaking type-advantage wise, picking the starter Rowlet would give you a good advantage early on; Pichu is also found early on (I picked one up myself and love my little Bleu); Grubbin's evolutionary line is bug/electric, evolving first at level 20, and again at Vast Poni Canyon; Magnemite can be found (most notably) in the city; Oricorio's Pom-Pom Style is another potential option, although not the best one; Petilil/Cottonee (depends on the game) is another potential option.
Oh, and having normal types learn electric moves means you'll always have a nice trick up your sleeve ;P

You have your pick of the litter! I'm sure you'll find something that suits you and your team.

~Rio

Answer 2

If you are talking about just Alolan Pokemon or Alolan forms then I'll help you out. I'll put some Pokemon I know can be found in-game but are not from Alola for e.g Magnemite can be found in game during themain story!

Pichu can be caught really early and you can evolve it into Alolan Raichu which can counter Water Types.

Grubbin which evolves into Vikavolt, if you want a counter right now, then don't get Grubbin because the evolution from Charjabug to Vikavolt will happen very late into the story

There are more but that are some suggestions.