you have to surf for it
on route 223
on route 223
route 223 or route 230
fish on route 223
You can get rain dance on route 223
Route 223 (Water Surface)
route 223 - 230 super rod
North of Sunyshore City. It leads you to the Pokemon League.
It is impossible to capture a Mantine in Pokemon Platinum. However you can capture a Mantyke, its pre-evolution, on route 223 by surfing and then evolving it by leveling it up with a Remoraid in your party. There is a 10% chance of encountering a Mantyke on route 223.
route 223 and in the huge field past valor lakefront
You can go fish at route 223 and route 230 with a super rod and eventually you'll find one
If your talking about octillery go to route 223 or whatever and use super rod