One IslandFireRed&LeafGreen
"The first Sevii Island and home to Celio's Pokemon Net Center. You arrive here after the Elite Four to help Celio establish a network link with the Hoenn region."
ONE ISLAND MAP
Hub island with Kindle Road heading north toward Mt. Ember. The town itself is just a few buildings clustered around the dock and Pokemon Center.
Pokemon Encounters
Fishing and surfing only. Shellder at 40% and Horsea at 40% cover the Super Rod, with Seadra at 4% as the uncommon pull. Tentacool at 95% while surfing. No grass encounters on the island.
Old Rod1
Good Rod3
Super Rod9
Magikarp
Also found in 41 other locations
ITEMS
Carbos boosts Speed and hidden treasures including a Star Piece and Big Pearl dot the area. Itemfinder sweep catches everything else.
Carbos
A nutritious drink for Pokemon. It raises the base SPEED stat of one Pokemon.
Carbos
A nutritious drink for Pokemon. It raises the base SPEED stat of one Pokemon.
Ether
Restores a selected move's PP by 10 points for one Pokemon.
Max Repel
Prevents weak wild Pokemon from appearing for 250 steps.
Big Pearl
A quite-large pearl that sparkles in a pretty silver color. It can be sold at a high price.
Pearl
A relatively small pearl that sparkles in a pretty silver color. It can be sold cheaply.
Star Piece
A shard of a pretty gem that sparkles in a red color. It can be sold at a high price.
Stardust
A pretty red sand with a loose, silky feel. It can be sold at a high price.
Ultra Ball
A very high-grade BALL that offers a higher Pokemon catch rate than a GREAT BALL.
One Island Guide
Islands One through Three unlock after you beat Blaine on Cinnabar Island. Bill takes you there as part of the story. Islands Four through Seven require beating the Elite Four first, then completing Celio's Ruby and Sapphire quest on One Island to get the Rainbow Pass.
You can physically reach all seven islands without it, but evolved Johto Pokemon only show up in the wild after you get the National Dex. That means 60 or more Pokedex entries plus completing Celio's quest. If you're only seeing Kanto species, that's why.
Old Rod only catches Magikarp. Good Rod adds Horsea, Poliwag, and Goldeen depending on the area. Super Rod is where the good stuff lives: Gyarados, Seadra, Staryu, Kingler. You get the Old Rod in Vermilion, Good Rod from the Fishing Guru south of Lavender Town, and Super Rod from his brother on Route 12.
If the encounter table shows Surfing or any Rod encounters, yes. Surf itself is HM03, found in the Secret House deep inside the Safari Zone. You also need the Soul Badge from Koga in Fuchsia City to use it outside battle.