you can't get to any of the Sevi island in Pokemon Heartgold and soul silver
the top left
i have no clue
The fourth gym leader in Pokemon Soul Silver is in Ecruteak City.
cindber island
The Cinnabar Island
it's impossible
Seafoam island is in the Kanto region in Heartgold and Soulsilver.
I believe the Top Right island.
You can't. New Moon island is in Sinnoh.
East of Cinninbar Island and southeast of Fucshia City.
The fourth gym leader hates ghost type pokemon. ex:Gastly
you have to get hm whirlpool