Water Labyrinth — Pokémon FireRed & LeafGreen+
Every wild Pokémon here, by encounter method.
Water Labyrinth lists 14 Pokémon across 7 encounter methods (surf, old rod, good rod, good rod, and more), between level 5 and 40. One of them is on no other route's wild tables in this guide: Togepi.
Water Labyrinth in other guides
The same area in other ROM hacks on this site. Each one has its own encounter table.
Opens up at Champion — the postgame. 2 trainers here: