All you got to do is go to fight area and go to the right where those guys were at then use hm surf and there you are!I hope that helped!
You can go fish at route 223 and route 230 with a super rod and eventually you'll find one
There are a few places you can find a dewgong in on Pokemon Platinum version. You can find him on Victory road, route 226, and route 230. If you catch a Seel you can also get Dewgong by leveling Seel up to level 34.
In Pokemon Platinum, the player can reach Route 228 by heading through Route 226 to come out on the north end of Route 228.
you can battle them on routes 224 and 230 in platinum
You can get him/her on route 224
route 223 or route 230
route 223 - 230 super rod
beat the elite four then follow route 230 and route 225
You can go fish at route 223 and route 230 with a super rod and eventually you'll find one
Pastoria city with the super rod and route 230 with super rod
You can hatch the egg given to you by Cynthia or find them on Route 230 with the Poké Radar.
You can find them at these places: Route 212 South, Route 213, Route 222, Route 223, Route 224, Route 230, Pastoria City, Sunyshore City, Pokemon League. (Fish with Good Rod.)
There are a few places you can find a dewgong in on Pokemon Platinum version. You can find him on Victory road, route 226, and route 230. If you catch a Seel you can also get Dewgong by leveling Seel up to level 34.
In the fight area you can access the Battle Frontier, and route 225 to Survival area, or route 230 to Resort area.
After obtaining the national pokedex, Dustox can be found at these areas THEY ARE RARE Eterna Forest Route 205 (North) Route 224 Route 229 Route 230
There's no Route 505 in Pokemon Platinum.
There is not a route 233 on Pokemon platinum.