seventh badge is cinnabar island. Fly to Pallet Town, surf south. Then go into pokemon mansion and find the secret key to unlock the gym
go through victory road with all gym badges
you have 2 have @ least 5 badges than you go 2 pallet town and you sail on the water
they are pass victory road to get to victory road you go to the west of viridian city then get all badges and get surf and strengenth
you go to the eliet 4 and finesh the game.
You go to Viridian City and get the 8th one.
you should go to gamestop
First surf down from pallet town then go into Pokemon mansion and get the secret key then go into the 7th gym and beat blaine.
you have to go into the pokemon mansion on cinnabar island and navigate your way around there untill you find the key
You have to go to Silph Co in Pokemon LeafGreen. You have to go there to get the Silph scope, which you need to advance.
After beating team rocket in every place: Mt moon, Pokemon tower, Game corner, Silph co. Then get 7 badges then you can go in the viridian city gym.
Go to the Pokemon league
you cant go underwater in leafgreen!!