Quick answer

Boss drop → NPC hand-in → coordinates → Radar

Every main island unlock follows the same pattern: defeat the required encounter, pick up its named quest item, return it to the correct NPC, accept the new coordinates, and follow the registered Radar marker. If the marker is missing, the previous hand-in is not fully complete.

Island Progression

Unlock routes in story order

03
Desert region · First new route

Unlock Island 3

Defeat the Giant Piranha, collect its Piranha Skeleton, return it to the Island 2 quest giver, and receive the Flash Drive containing new coordinates.

Previous boss
Giant Piranha
Required item
Piranha Skeleton
Route reward
Flash Drive
Next objective
Pufferfish
View Island 3 unlock guide →
04
Rocky region · Second new route

Unlock Island 4

Defeat Pufferfish, keep the Pufferfish Fin, and return it to the Island 3 Tourist. Accept the coordinates before checking your boat Radar.

Previous boss
Pufferfish
Required item
Pufferfish Fin
Hand-in NPC
Tourist
Next objective
Terrorizing Bird
View Island 4 unlock guide →
05
Final region · Military base

Unlock the Volcano / Military Area

Defeat the Terrorizing Bird / Albatross, collect the Albatross Head, complete the Island 4 trophy hand-in, and follow the final coordinates.

Previous boss
Terrorizing Bird
Required item
Albatross Head
Route reward
Final coordinates
Next objective
Whale experiment
View Volcano unlock guide →

Route troubleshooting

Why the next island is not showing

Boss drop was left behind

Return to the encounter area and look for the named Skeleton, Fin, or Head required by the quest.

Wrong NPC

Give the trophy back to the NPC connected to that island's quest chain, not a general merchant.

Dialogue is unfinished

Continue the hand-in until you actually receive coordinates or the route item.

Radar was not checked

Return to the boat and confirm the new marker before sailing. Do not rely on a copied compass heading.

After arrival

What each new region starts

FAQ

Island unlock questions

How do I know an island is unlocked?

The quest hand-in finishes, you receive its route reward or coordinates, and a new destination appears on the boat Radar.

Can I sail directly to a later island?

Follow the active story route. Later areas and their interactions depend on earlier boss drops and quest hand-ins even if you know their direction.

What should I do if the Radar is unchanged?

Retrace the previous encounter: boss defeated, named trophy collected, correct NPC found, dialogue completed, and coordinates accepted.

Where is the complete story order?

Use the Full Walkthrough to see island unlocks and boss fights in one continuous route.

First island unlockHow to Unlock Island 3Start the island progression route