Quote from Bulbapedia: Sootopolis can only be reached by diving through an underwater cavern or by Flying. Sootopolis is surrounded by Route 126. here is a link to the main article:
http://bulbapedia.bulbagarden.net/wiki/Sootopolis_City
The sapphire is on Six Island. You need a Pokemon to use cut on the dotted door of the cave.
In Pokemon Sapphire, Latios can be found in Southern Island.
No.
Surf to an island
i don't know ,but i heard you have to get a mirage island compatible Pokemon
get an Eon ticket!!
there is no cinnabar island in sapphire. cinnabar is on firered and leafgreen. also in Pokemon yellow special pikachu edition ^_^ don't forget that dude...
in southern island there was latias and latios you will meet latias in Pokemon sapphire and latios in Pokemon ruby
fix the machine on island 1 find the ruby and the sapphire stones
You need to have a Pokemon that knows cut. Stand in front of the Dotted Hole entrance and then use cut. When you get inside, there will be a hole. Go in and then you will need to fall in the right hole and then the Sapphire but a scientist will take it before you take it. Go after him after he tells you the password to get in Team Rocket's Warehouse. Battle them all and they will leave and then he is at the back. Defeat him and he will give you the Sapphire back. Then take it to one island. Put it in and then you can trade Pokemon with Trainers from the Hoenn Region.
rainbow island
I believe that that's not possible.