Route 20 Pokémon Yellow · Route
A stretch of sea between Route 19 and Cinnabar Island, split by the Seafoam Islands. You must go through the Seafoam Islands to join the two halves. You arrive after the Soul Badge and Surf, on the way to Cinnabar Island.
- Wild Pokémon
- 3
- Items
- 0
- Trainers
- 10
- Needs
- Surf, Strength
Connects to: Route 19 · Cinnabar Island · Seafoam Islands
Position on the Kanto town map
Wild Pokémon
| Pokémon | Type | Lv. | Chance |
|---|---|---|---|
 Tentacool | WaterPoison | 5–40 | 100% |
| Rod | Pokémon | Lv. | Chance |
|---|---|---|---|
| Old Rod |  Magikarp | 5 | 100% |
| Good Rod |  Goldeen | 10 | 50% |
 Poliwag | 10 | 50% | |
| Super Rod |  Tentacruel | 20–40 | 40.2% |
| Tentacool | 20 | 39.8% | |
 Staryu | 30 | 19.9% |
Grass, cave and surfing chances are the Generation I encounter slots (10 slots weighted 51, 51, 39, 25, 25, 25, 13, 13, 11 and 3 out of 256); the Super Rod picks from four slots weighted 102, 76, 51 and 27, the Good Rod is 50/50 and the Old Rod always hooks a level 5 Magikarp. Where to find every Pokémon.
Trainers
| Trainer | Pokémon | Prize |
|---|---|---|
 Swimmer |  Shellder 31 Cloyster 31 | ₽155 |
 Beauty |  Seadra 30 Horsea 30Seadra 30 | ₽2,100 |
| Beauty |  Seaking 35 | ₽2,450 |
 Jr. Trainer♀ | Tentacool 30Horsea 30 Seel 30 | ₽600 |
| Swimmer | Staryu 35 | ₽175 |
| Swimmer | Horsea 28Horsea 28Seadra 28Horsea 28 | ₽140 |
 Bird Keeper |  Fearow 30Fearow 30 Pidgeotto 30 | ₽750 |
| Beauty | Shellder 30Shellder 30Cloyster 30 | ₽2,100 |
| Jr. Trainer♀ | Goldeen 31Seaking 31 | ₽620 |
| Beauty | Poliwag 31Seaking 31 | ₽2,170 |
Prize money is the trainer class’s base amount times the level of their last Pokémon.
Items
No items to pick up here.
Tips
- Wild encounters while surfing are only Tentacool.
- Fishing with the Super Rod can catch Staryu and Tentacruel.
- Seafoam Islands needs Strength to push boulders, and Articuno is inside.
- The Swimmers, Beauties and Jr. Trainers carry Water Pokémon, so use Electric and Grass attacks.
Walkthrough: Part 11: Seafoam Islands, Cinnabar Island and Blaine
FAQ
How do I get to Cinnabar Island in Pokémon Yellow?
Surf down Route 19 and Route 20 through the Seafoam Islands, or Surf south from Pallet Town on Route 21.
Do I need Strength on Route 20 in Pokémon Yellow?
Yes, you need Strength to push boulders inside the Seafoam Islands.
Can I catch Staryu on Route 20 in Pokémon Yellow?
Yes, by fishing with the Super Rod.
What Pokémon can you catch in Route 20 in Pokémon Yellow?
3 species: Tentacool, Tentacruel, Staryu. The tables show levels and encounter chances from the game data.
Sources & picture credits
- Route 20 (Bulbapedia)
- pret/pokeyellow (decompiled game data)
- Map: Kanto_Route_20_RBY.png
- Town map: Kanto_Town_Map_RGBY.png
Guide text is original retrogameindex writing, checked against Bulbapedia and the game data. Wild Pokémon, encounter rates, items, trainers, gifts and shops come from the pret/pokeyellow decompilation of the English game (pret/pokeyellow e89ead154b). Maps and sprites © Nintendo / Creatures / GAME FREAK, archived from the Bulbagarden Archives (listed on the image gallery).