How do you get Blastoise in sapphire?

You can't get Blastoise directly in Pokémon Sapphire. You need to evolve Squirtle into Wartortle and then Wartortle into Blastoise. Here's how:

1. Catch Squirtle:

* You can find Squirtle in the Oldale Town area.

* You need to find a hidden patch of grass behind the house to the right of the Pokémon Center.

* Squirtle will appear at a low level (around level 5).

2. Evolve Squirtle into Wartortle:

* Squirtle will evolve into Wartortle at level 16.

* You can level it up by battling wild Pokémon.

3. Evolve Wartortle into Blastoise:

* Wartortle will evolve into Blastoise at level 36.

* Keep battling wild Pokémon to level up your Wartortle.

Important Note: You can't find Squirtle in the wild after the Oldale Town area, so be sure to catch it before moving on.