What move is better hydro pump or hydro cannon?

Answer 1

Hydro Cannon is unreliable, as Hydro Pump outdamages Hydro Cannon in two turns, as Hydro cannon has to recharge on one of the two turns, rendering the attacker a sitting duck, UNLESS Hydro Pump misses on one of the turns, due to its terrible accuracy.

Basically, Hyper Beam and its variations are often deemed ineffective due to the worthless recharging turn, which simply allows the opponent to set up, attack or just get a free switch to a counter if some sort.

Competitively, Hydro Pump is far superior as it does not require recharging and has a 240 base power in two turns (360 after factoring in STAB) while Hydro Cannon only has a 150 base power in two turns (225 after factoring in STAB).

However, in-game, both moves have their own niches. Hydro Cannon, especially in Elite Four battles, can one shot KO many targets and the recharging turn can be remedied by switching out while the opponent sends out another Pokemon. Hydro Pump can be used if you want your Pokemon to stay on the field longer.

However, stick with Hydro Pump when it comes to the Battle Tower or the Battle Frontier.

Although the two moves are extremely powerful, both have their own flaws. Hydro Cannon gets a flaw of Recharging and maybe a shaky 10% chance of missing, while Hydro Pump gets a flaw of a terrible 80% accuracy, which means it's going to miss on 1 out of 5 strikes.

Thus, I recommend Surf or if your Pokemon is a physical powerhouse like Feraligatr or Swampert, don't choose any of them and choose Waterfall or Aqua Tail instead. They're reliable, their accuracy are consistent (in exception with Aqua Tail) and they can still do damage. However, if you want your really wanted OHKOs or 2HKOs, then use Hydro Pump or Hydro Cannon.

Now, what's better? Well, competitive players prefer Hydro Pump to blow through enemies without a need to waste a turn (in exception with missing) and simply, in the opinion of I, a competitive geek, I'd say Hydro Pump's the better option..