One Island — Pokémon FireRed & LeafGreen+
Every wild Pokémon here, by encounter method.
One Island lists 12 Pokémon across 6 encounter methods (surf, old rod, good rod, good rod, and more), between level 5 and 40.
One Island in other guides
The same area in other ROM hacks on this site. Each one has its own encounter table.
The original game's table for this area:
Opens up at Volcano Badge — One, Two and Three Island.
Surf Lv 5-40
Old Rod Lv 5
Good Rod Lv 5-15
Good Rod Lv 5-15
Super Rod Lv 15-35
Horsea40% · Lv 15-25
Shellder40% · Lv 15-25
Gyarados15% · Lv 15-25
Seadra4% · Lv 25-35
Psyduck1% · Lv 25-35Super Rod Lv 15-35
Krabby40% · Lv 15-25
Staryu40% · Lv 15-25Gyarados15% · Lv 15-25
Kingler4% · Lv 25-35
Slowpoke1% · Lv 25-35TMs found here
- HM08 Dive — One Island Pokémon Center 1F (pick up)