* Whilmer is not a Pokemon that can be found in the wild in Pokemon Sapphire. Whilmer is only available in Pokemon Ruby, and even then, only through breeding.
* Super Rods are used to catch Pokemon that appear in the water. While Whilmer is a Water-type Pokemon, it cannot be caught in the wild in Sapphire, so you cannot use a Super Rod to catch it.
To get a Whilmer in Pokemon Sapphire, you would need to trade with someone who has a Whilmer from Pokemon Ruby.