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Isles of Abyss › Ship fuel

Once Human Ship Fuel: How to Refuel Your Boat in Isles of Abyss

LiveUpdated 2026-10-26 · Game v3.1.1Oil farm spot in Reefshadow Bay

By the Once Human Guide crew — a small fan team led by Yao · from patch notes + videos

Short answer: the Fuel Propeller is the only ship part that burns fuel. The dev blog says it runs on Black Tide Fuel, made from the abyssal sea oil a Drilling Well pumps up. Early on, most players smelt fish into mixed fuel in a furnace after unlocking Fish Transformation in the Production Tech tab. Sails and oars need no fuel, and electric propellers run on generator power, so a solar-powered electric setup is the way to stop refuelling altogether.

Hazards on the way:Mist of Deceit · oil farm spotGiant Squid · grabs hullin Reefshadow Bay · Fragrant Cape
On this page
  1. Which ship parts burn fuel
  2. Get fuel from fish (the early route)
  3. AFK oil farm with Drilling Wells
  4. Sails vs engines: how to use less fuel
  5. Fix: out of fuel at sea
  6. Coming from the base game?
  7. FAQ
  8. What changed

Which ship parts burn fuel

The dev blog lists ship propulsion in four steps: manual (oars) → sails → fuel → electric drive. Only the fuel step uses fuel. Everything else on the drive train runs on wind, muscle or electricity. If you haven’t built a hull yet, start with How to build a ship.

part runs on speed it adds in Build Mode note
Boat oar nothing about 25 each the starter option
Small sail / large sail wind about 45 / about 53 fast downwind, slow upwind; the small sail includes a wind vane
Fuel Propeller fuel (Black Tide Fuel per the dev blog) same as the Electric Propeller needs topping up
Electric Propeller generator power same as the Fuel Propeller solar panels work, wired like on land
Advanced Fuel / Advanced Electric Propeller fuel / power a little more than the basic pair, equal to each other a main-story step asks you to build one of them
Side thruster — adds handling, not speed makes turning easier

src: dev blog (2026-10-16) · OreaChief fQMgsfXiAEw @11:00–12:16 (speed values read from his Build Mode; actual speed depends on the boat) · Krithi KwssiMc_VAI quest tracker

Propellers, side thrusters and boosters all need Precision Gear Set, which is the real bottleneck early on. In Build Mode the left panel shows the ship’s Speed; you can add several sails or propellers, but plan around that number rather than stacking parts blindly.

Isles of Abyss Build Mode showing a wooden raft with several sails and a Speed value of 181 in the left panel Screenshot: Krithi, “The EASIEST AFK Oil Farm in Isles of the Abyss!” on YouTube, at 0:17

Get fuel from fish (the early route)

This is the route most players use in the first hours, because you’ll be fishing anyway.

  1. It sits in the Production tab of the Tech tree. It lets you turn fish into acid at a synthesis bench, or smelt fish into portable mixed fuel at a furnace. A later Tech node cuts the crafting time of both by 30%.

    src: OreaChief fQMgsfXiAEw @08:30 · Gotcha Beast KJvFq__cWp8 @03:36

  2. The local fisherman gives a short chain that teaches fish → acid, fish → mixed fuel, and then Fish Paste. test-server footage

  3. Different fish give different amounts. Bigger catches give more, and sharks give the most. That’s why some players breed fish in a Tidal Cage once they find a species they like.

  4. A Trawl Net pulls in fish and floating supplies while you sail, so the fuel stock grows on every trip. Check the ship vault for the catch.

  5. A furnace on the ship lets you smelt at sea. Bigger automated fuel production is better kept at your land base.

    src: Gotcha Beast KJvFq__cWp8 @02:05 · Grizl o5-Cq9fuLF0 @02:40 (furnace on the ship)

How much mixed fuel each fish gives, and how far one unit takes a Fuel Propeller, haven’t been published yet.

AFK oil farm with Drilling Wells

Fish keep you going early on. For a hands-off supply, put Drilling Wells on the ship. One creator’s setup, buildable a few hours into the scenario:

  1. Wooden platforms and a few sails. He reports about 80–90 km/h on the water with no engines at all.

  2. Two solar panels are enough to power three wells at once. Both the generators and the wells can be found early in settlements: recycle them there and place them on your deck.

  3. Set each well’s output to Barreled Crude Oil, which is tied to an Oil Field Area. His spot is off a small island northwest of a Lv.10 settlement in Reefshadow Bay, around (-6863, -2864) on the map. The wells keep pumping as long as the ship stays in the area.

Ship deck with two solar panels wired to a Drilling Well, with more wells and sail masts around them Screenshot: Krithi, “The EASIEST AFK Oil Farm in Isles of the Abyss!” on YouTube, at 0:41

Isles of Abyss map of Reefshadow Bay with the oil farm spot marked off a small island near a Lv.10 settlement, cursor at -6863, -2864 Screenshot: Krithi, “The EASIEST AFK Oil Farm in Isles of the Abyss!” on YouTube, at 0:43

The Drilling Well menu lists four outputs, each tied to an area: Barreled Crude Oil (Oil Field Area), Dirty Water (all areas), Sea Water (ocean area) and Polluted Water (pollution zone). In the video one well holds up to 4,000 units.

Drilling Well menu with Barreled Crude Oil selected for the Oil Field Area, plus Dirty Water, Sea Water and Polluted Water options Screenshot: Krithi, “The EASIEST AFK Oil Farm in Isles of the Abyss!” on YouTube, at 0:48

The dev blog says the Drilling Well extracts abyssal sea oil and that Black Tide Fuel powers the Fuel Propeller and raises the Generator’s power cap. According to a dev-blog walkthrough, this oil isn’t found on the islands, so the well is the only source. How barrels of crude become Black Tide Fuel (which bench, what ratio) hasn’t been published yet; we’ll add it once the developer confirms. Black Tide Fuel is also a Haywire Zone resource; see Haywire Zones for that side. The spot above sits in Mist of Deceit waters, so bring the counter item.

src: Krithi KwssiMc_VAI @00:12–00:48 · dev blog (2026-10-16) · Doomeris zIDlwmX7CPg @14:19 · momsbisburi ZHiW-FU_tCU @05:06

Sails vs engines: how to use less fuel

  • Sail downwind, motor upwind. A sail is only fast with the wind behind it; turning into the wind kills your speed. Engines hold a steady speed (one creator saw about 85–87) whatever the wind, but they burn fuel or power.
  • Go electric as soon as you can. The electric propeller adds the same speed as the fuel one and never needs refuelling once it’s wired to a generator. Solar panels are the easy choice. A main-story step asks for an Advanced Fuel Propeller or an Advanced Electric Propeller, so you can skip fuel there too.
  • Late game, drop the sails. One creator’s endgame speed build is two thrusters, four advanced electric propellers and two boosters, with no sails, because sails drag you down when the wind is wrong.
  • Keep the hull light. A sails-only wooden raft already reaches 80–90 km/h in Krithi’s video, which is plenty for an oil run.

src: SysFem64 WNM-tSNh52w @03:13 · OreaChief fQMgsfXiAEw @11:33 · MaleOreo eHuqSVMlzvg @03:10

Fix: out of fuel at sea

  1. Raise a sail and head downwind. Sails and oars need no fuel. Keep at least one sail on board for this.
  2. Check your supply bench. One creator showed that a ship’s supply bench can draw on materials, fuel included, stored at the land base, even far outside the territory. If it doesn’t work, check the territory-supplies option in the anchor/core settings (see Ship base).
  3. Smelt fish on board. If you carry a furnace and have Fish Transformation unlocked, turn your Trawl Net catch into mixed fuel on the spot.
  4. Summon the ship. If you’re stuck or drifting, use Summon Vehicle or Relocation to put the saved ship back where you need it.
  5. Rebuild the drive. Swap the Fuel Propeller for an electric one plus a solar panel so it doesn’t happen again.

Coming from the base game?

Outside the scenario, cars and bikes run on Portable Mixed Fuel, and the old fuel farms still work for vehicles. In Isles of Abyss the fish-into-fuel recipe also makes portable mixed fuel, but the patch notes don’t say whether the Fuel Propeller accepts it directly or only takes Black Tide Fuel. For the wider scenario, see the Isles of Abyss hub and the beginner guide.

FAQ

What fuel do you use in a ship in Once Human?
The Fuel Propeller (and the Advanced Fuel Propeller) is the only ship part that takes fuel. The dev blog names Black Tide Fuel. Creators also smelt fish into mixed fuel to keep their propellers running. Sails and oars don’t burn fuel, and electric propellers need a generator instead.
How do you get fuel in Once Human Isles of Abyss?
Two routes. Fish: unlock Fish Transformation in the Production Tech tab, then smelt fish in a furnace; sharks give the most. Oil: fit Drilling Wells and a power source to your ship, anchor in an oil field area and let them pump. The dev blog says abyssal sea oil becomes Black Tide Fuel; the exact refining step hasn’t been published yet. We’ll update this once the developer confirms.
How do you refuel a ship in Once Human?
Put fuel into the Fuel Propeller from your stock. A supply bench on the ship can also draw on materials, fuel included, stored at your land base, even when the ship is far from your territory (one creator showed this on 23 Oct).
What happens when my ship runs out of fuel?
Sails and oars don’t need fuel, so keeping one sail on board means you can still limp home downwind. If you’re stuck, Summon Vehicle or Relocation puts the ship back on open water.
Is the electric propeller better than the fuel propeller?
They add the same speed in Build Mode, and so do the advanced versions of each. The electric one never needs refuelling once a generator such as a solar panel is wired to it, which is why most creators move to electric propellers.
How do I finish “Build an Advanced Fuel Propeller or an Advanced Electric Propeller on the ship”?
This is the main-story step “Build one of the following facilities on the ship”, and either propeller completes it. Unlock one of them in the Tech tree, then place it on your ship in Build Mode. Propellers need Precision Gear Set, and the item database lists Coral Ore for the advanced pair too (see [materials](/isles-of-abyss/materials/)). The electric one needs a generator wired to it, so pick it if you already have solar panels; the fuel one keeps burning fuel. Both advanced versions add the same speed, a little more than the basic pair (OreaChief).

What changed

  • v3.1.1 · 2026-10-25FAQ for the main-story step “Build an Advanced Fuel Propeller or an Advanced Electric Propeller on the ship”.
  • v3.1.1 · 2026-10-25Page created.

Sources

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