Seafoam Islands are a micro-archipelago in Kanto environed within Route 20.
It is a labyrinthine domain of islands that interconnectively encompasses two diagonally adjoined, nearly identical islands. Due to the exterior impassability of Route 20, voyagers must interiorly travel through both islands in order to reach the contradirectional segments of the route; therefore, this area must be passed through in order to access Cinnabar Island for the first time.
Notable miscellaneous
Articuno
An overworld-interactable Articuno inhabits the bottommost floor of the caves, on the middle-south island of the floor.
While this Articuno is not catchable, you will automatically register its seen-data entry in your Pokédex by battling it; this is needed for the Mew quest, which stipulates that 150 seen-data entries of Generation I Pokémon is needed in order to access Mew's inhabiting island, including Articuno's.
If you have battled this Articuno yet have lost its seen-data entry, you can use the restitutionary machine in Professor Oak's lab in Pallet Town in order to recover it.
Nurse Joy
A Nurse Joy is found stationed on B4F available to Kanto champions; usage of this service spares the strenuity of making Pokémon Center trips in order to heal, allowing trainers in the cave to proximately heal their battle-ravaged Pokémon.
She will heal the entirety of your lineup for 
1,500 per recuperation.
A move tutor for the move Icy Wind can be found on the westmost path of Seafoam B4F, in the water. He will teach the move to any compatible pokemon for 5,000.
Wild Pokémon
1F
Land
B1F
B2F
Land
B3F
Land
B4F
Land
Surfing
|
| Pokémon | Level range | Times | Held Item | Rod | Rarity Tier |
|---|
- Pink-colored names denote that this Pokémon is exclusively encounterable for members in this area.
- All Pokémon tabulated here can only be encountered via fishing; they are not Surf-encounterable.
|
Items
B1F
| Item | Quantity | Cooldown | Location |
|---|
 |
Ultra Ball |
1 |
Not respawnable |
Interposed between two stalagmites north of the middlemost B2F ladderway |
 |
Pearl |
1 |
Not respawnable |
Hidden Item. In the tall stalagmite of the dead-end caused by a white boulder south-east from the westmost B2F ladder |
B2F
| Item | Quantity | Cooldown | Location |
|---|
 |
TM13 - Ice Beam |
1 |
Not respawnable |
Southeasternmost corner |
B3F
| Item | Quantity | Cooldown | Location |
|---|
 |
Ice Heal |
1 |
Not respawnable |
Between the two eastmost ladders of the lower ground area |
 |
Revive |
1 |
Not respawnable |
Adjacent to the southmost bridge of the west pond |
|
Pearl |
1 |
Not respawnable |
Hidden Item. In the second tall stalagmite from the end of the dead-end east of the westmost B2F ladder |
B4F
| Item | Quantity | Cooldown | Location |
|---|
 |
Escape Rope |
1 |
4 days |
Lootable capsule found on the centermost terrain |
 |
Nugget |
1 |
Not respawnable |
Hidden Item. In the centermost small stalagmite of the island reachable from the second eastmost B3F ladder |
NPC Battlables
Articuno
1,500 per recuperation.
