What it does
Water Spout is a Water-type special spread move that hits both opposing Pokémon. Power is calculated as 150 × current HP / max HP, starting at 150 at full health and dropping linearly. At half HP it's roughly 75; at near-empty it's single digits. Spread moves hit each target at ×0.75 in doubles, so at full HP each opponent takes the equivalent of about 112 base power — still enormous.
Who runs it
Blastoise carries Water Spout in roughly 30% of Champion runs. Its solid Special Attack and Special Defense give it a real chance of surviving a hit before it moves, which matters — you want to be at full HP when you press the button. Water Spout forces both opponents to respond immediately, usually spending at least one action addressing Blastoise directly.
How to use it
The whole game is 'stay healthy and keep firing.' Every point of HP lost is a direct cut in damage output. Rain doubles the pressure: under Rain Dance, Water-type moves get ×1.5, pushing full-HP Water Spout into territory almost nothing survives cleanly. The standard approach is to pair Blastoise with a rain setter and fire on turn one before the opponent can chip you down.
Opponents know this, so they will try to chip HP fast. Use Protect to give your partner a free turn to clear a threat, then come back at full HP. Positioning Blastoise as the lead means you threaten spread damage immediately — your opponent has to either deal with it or eat two consecutive Water Spout hits.
Tips & strategy
Speed is the other lever. If you move second, you've already taken a hit before Water Spout lands, and at anything below 75% HP the power starts feeling ordinary. Tailwind support lets Blastoise outrun threats it normally couldn't. Fake Out from a partner buys the turn you need to stay untouched. Once HP drops below half, the move is no longer the threat it was — consider switching rather than clicking it out of habit.