Complete the scientist’s request
On Volcano island, find the scientist in yellow protective clothing. Give him five fish to receive the Fish Bucket. Current guides report that the request accepts ordinary fish, so use disposable catches rather than a rare Drip or quest object.
Before casting the Bucket, make inventory room for an entire whale body. Bring a reliable ranged weapon, ammunition, and cooked healing fish. The Assault Rifle is a strong sustained-damage option in current coverage, but movement matters more than a single named loadout.
Defeat and preserve the first whale
Equip the Fish Bucket as bait and cast into the water around Volcano island. The regular Bowhead Whale can charge on land and leap high before a body slam. Stop shooting when you need a clear sprint path, move away from the projected landing area, and attack after the impact.
Pick up the intact Bowhead Whale when it dies. Do not sell it, cook it, or break it into food. Its body is the trigger for the actual final encounter.
Start the mutated fight
Carry the whale up the wooden route toward the crater. Heal, reload, and place any loose supplies before the final step. Dropping the body into the lava immediately summons the Mutated Bowhead Whale.
The mutated boss combines three major pressures:
- long ground charges that punish shooting in place;
- aerial body slams that demand a committed sprint;
- scattered lava that removes previously safe ground.
Keep the camera wide enough to see the whole body, move first during a telegraph, and fire during the recovery after a charge or slam. As the arena becomes less safe, preserve a clean route rather than circling through fresh lava.
Finish the game correctly
Collect the Whale Fin after the boss dies and return it to the scientist. He provides the keys for the RHIB military boat. Enter that boat and use its steering wheel to trigger the ending; the final kill alone does not roll the complete story state.
Patch 1.0.4 nerfed the Whale without exact public numbers and made the intended path toward the final island easier to see. This fight guide is therefore version-sensitive through 1.0.10.