If you use dive in dark patches of water then go in the seaweed then you can catch chinchou.
you can catch water Pokemon by surfing on water and by using all the rods
Rectha
You can capture wailmer in ruby, sapphire and emerald on most routes where water is you can find either by using a rod or by using surf.
At victory road............ in the water....
You can.
You do not need a Wailord to catch a Registeel in Pokemon Emerald. You may need a Wailord or any other water-type Pokemon to surf to the place where you catch Registeel, but other than that, you don't need a Wailord.
water it two times and it will attack you
You can find it if you fish in the water near the Day-care.:)
any where in the game on water or land just look hard
If you use dive in dark patches of water then go in the seaweed then you can catch chinchou.
By the water outside of the Evergrande City Pokemon Center, use a super rod. You'll find it about 15% of the time.
under water place
You can find them if you fish in routes 102, 117 or in the water at Petalburg city with a good rod.
catch it on the route beetween mauville and fortree cities in the water(it's really rare).
In Emerald, Pokemon can be found in Grass, Water, and Caves. There are 385 Pokemon in total.
You have to go to Sky pillar (Surf right from that water town) and catch (or run or kill, whatever you want, probably catch) Rauquaza.