Its simple, when you enter the town you go up the 1st lot of stairs onto a big solar panel pathway just keep following that path to the right and you should be at the lighthouse. if he ain't there then tough.
In the lighthouse in Sunyshore city
You can get seals from the Sunyshore City market.
To get HM7 (Waterfall) in Platinum you can get it at Sunyshore City talking to Jasmine at the north of the city.
The 8th and last gym is in Sunyshore City.
you can find them under ground or there is one in sunyshore city.
It is in Sunyshore City.
you must talk to him in the lighthouse, in sunyshore then you can go in
In the lighthouse in Sunyshore city
Volkner is located in Sunyshore City.
the route on your way to sunyshore city
in sunyshore city
You can get seals from the Sunyshore City market.
victory road north of sunyshore city but you have to have the sunyshore gym badge to get there
Go up to the Lighthouse in Sunyshore City. You should see him there. Talk to him and then return to the Gym.
you can find it by the lighthouse in sunyshore city by the snorlax rock
The sailors near Sunyshore City.
North of Sunyshore City. It leads you to the Pokemon League.