Quick route

Follow the quest chain, not every optional catch

The main route advances by collecting the item needed for the next objective, defeating the required boss, and unlocking the next island or vehicle. Use the nine stages below in order. If an interaction is missing, return to the previous stage and confirm that its named quest item was collected and handed in.

Progress check

Find the first unfinished objective

Start at the top and locate the first box you cannot check. That stage—not the newest island you can physically reach—is your current story objective.

Complete route

Story progression, step by step

01
Opening objective

Where to Find Leeches

Gather the early quest resource and finish its hand-in to move the opening progression chain forward.

Open Leech guide →
02
Boss encounter

Defeat the Giant Piranha

Prepare your weapon and boat, then defeat the first major boss blocking the next phase.

Open Giant Piranha guide →
03
Island unlock

Unlock Island 3

Use the reward from the previous sequence to open the next destination and continue the main quest.

Open Island 3 guide →
04
Boss encounter

How to Beat Pufferfish

Complete the island objectives, survive its dangerous inflated phase, and claim the progression reward.

Open Pufferfish guide →
05
Island unlock

Unlock Island 4

Turn the previous boss reward into access to the next region. Confirm the hand-in if the route is missing.

Open Island 4 guide →
06
Boss encounter

Defeat the Terrorizing Bird / Albatross

Track the airborne boss, survive its attack windows, and collect its story progression item.

Open Terrorizing Bird guide →
07
Final area unlock

Unlock the Volcano / Military Area

Complete the required hand-ins and activate the route into the late-game military area.

Open Volcano unlock guide →
09
Ending

Return to the Mainland

Give the Whale Fin to the Scientist, receive the RHIB keys, and launch the military boat to trigger the credits.

Open ending guide →

Troubleshooting

If the next objective does not unlock

Check the drop

Pick up the named quest reward before leaving a boss arena.

Finish the hand-in

Return to the quest NPC and complete the previous exchange.

Use the correct vehicle

Keys belong to a specific boat or aircraft, not every nearby vehicle.

Return one stage

Reopen the previous detailed guide and verify its completion step.

FAQ

Walkthrough questions

Do I need every fish to finish the story?

No. The main route is driven by required quest items, bosses, hand-ins, and area unlocks.

Why did defeating a boss not unlock the next island?

Check the arena for its progression drop, then return to the relevant NPC. The hand-in often controls the unlock.

Does defeating the Mutated Bowhead Whale finish the game?

No. Collect the Whale Fin, give it to the Scientist, obtain the RHIB keys, and launch the military boat.

Can I keep playing after the credits?

Use the completed save to revisit unlocked areas and clean up optional fish, equipment, and achievements.

Start the routeWhere to Find LeechesBegin stage one of the walkthrough