You cannot find hydro pump. The reason is because it is not a TM. Most water Pokemon can learn it when they have reach a certain level.
There isn't a TM called hydro pump you can only get a Pokemon to use if it can learn it leveling up
Feraligatr can learn Hydro Pump at level 58 in Pokemon Crystal.
hydro isnt a TM.
Salamence can only learn Hydro Pump as an egg move in Pokemon Emerald.
Swampert does not learn Hydro Pump.
There isn't a TM called hydro pump you can only get a Pokemon to use if it can learn it leveling up
Hydro pump does 120 damage
Hydro pump is not a TM in sapphire.
Feraligatr can learn Hydro Pump at level 58 in Pokemon Crystal.
hydro isnt a TM.
Salamence can only learn Hydro Pump as an egg move in Pokemon Emerald.
Swampert does not learn Hydro Pump.
It's not a tm but certain pokemon learn it while leveling up
You will have to trade or make it learn hydro pump
You have to get a female Masquerain, and a male Pokemon that learns Hydro Pump and is in the Water1 egg group. (Example: Lombre or Swampert) Put both Pokemon in the Day-Care center then, you might find a Surskit egg. If, you do get an egg, then hatch it (by walking for a long time), then you will notice that your Surskit learns Hydro Pump. (By the way, this is the only way Surskit will learn hydro pump.)
Feraligatr learns Hydro Pump at Lv. 63.
You have to breed it with a Pokemon that knows hydro pump like a male gyarados or lanturn with a female sharpedo. When the egg hatches I think you will have a carvahna with hydro pump.