Quick answer

Give the Pufferfish Fin to the Tourist, then check your Radar

Defeat Pufferfish on Island 3 and collect its named quest drop, the Pufferfish Fin. Return it to the Tourist who gave you the Carrot, finish the hand-in, and accept the coordinates for Island 4. Return to your boat, open the Radar, and follow the newly registered route to the rocky island.

01 · Before you start

Complete the Island 3 Pufferfish chain

Island 4 is locked behind the main Tourist quest. Sailing around without completing the sequence will not create the destination marker.

  1. 1

    Trade an Endangered catch

    Give the Island 3 Tourist a qualifying catch to receive the Carrot boss bait.

  2. 2

    Summon Pufferfish

    Cast the Carrot in the Island 3 lagoon to begin the rolling boss encounter.

  3. 3

    Defeat the boss

    Use terrain to break its charges and avoid the poison trail in the later phase.

Previous routeHow to Unlock Island 3 Required bossHow to Beat Pufferfish

02 · Quest drop

Pick up the correct Pufferfish drop

After the boss dies, look for the distinct named progression item. Current guides call it the Pufferfish Fin, while some walkthroughs describe the same trophy as a tail. The important part is to keep the named boss trophy rather than ordinary meat.

03 · Hand-in

Return the Fin to the Island 3 Tourist

Take the Pufferfish Fin back to the same Tourist who traded you the Carrot. Complete the conversation and accept the coordinate reward. Do not leave after placing or showing the item if the dialogue has not fully advanced.

Completion signalIsland 4 coordinates received

The quest hand-in is complete when the route reward is accepted and a new destination can register on your Radar.

04 · Navigation

Follow the new Radar route

  1. 1

    Return to your boat

    After receiving the coordinates, head back to the vessel before trying to verify the destination.

  2. 2

    Open the Radar

    Confirm that the new marker or route has registered. This avoids relying on an absolute heading that may differ between saves or patches.

  3. 3

    Navigate by the marker

    Follow the updated Radar and keep checking it during the crossing.

  4. 4

    Identify the rocky island

    Island 4 begins the Tuna and Terrorizing Bird progression chain.

05 · Troubleshooting

Why Island 4 is not appearing

Pufferfish is still alive

The destination stays locked until the Island 3 boss chain is complete.

The Tourist will not advance

Confirm that you collected the named Pufferfish Fin or trophy—not an ordinary meat drop.

No coordinates appeared

Continue the Tourist dialogue and make sure the reward interaction fully completes.

The Radar is unchanged

Retrace the chain: Carrot acquired → Pufferfish defeated → Fin collected → Tourist hand-in → coordinates received.

06 · After arrival

Start the Tuna and Terrorizing Bird quest

Speak with the local quest NPC about the large bird. Island 4's main chain requires the Professional Boss Lure to catch a Tuna, then uses that Tuna to attract the Terrorizing Bird. Prepare ranged damage and cover before committing to the aerial boss.

Next progression bossHow to Beat the Terrorizing BirdCatch the Tuna, summon the bird, and survive its aerial attacks

07 · Common questions

Island 4 FAQ

Does defeating Pufferfish automatically unlock Island 4?

No. Collect the named Pufferfish trophy, return it to the Tourist, and accept the coordinate reward.

How do you know the route is available?

The Tourist hand-in completes, you receive the next coordinates, and a new destination registers on the Radar.

What should you do first on Island 4?

Activate the local Terrorizing Bird quest, then prepare to catch Tuna with the Professional Boss Lure.