Exploration
The Last Caretaker Sonar: How the Scan-50 Works, Where to Put It and the Deep Scan-500 Add-On
The Scan-50 Sonar shows the seabed in green up to a 50 m scan range and marks ores and other objects with a + sign, including things below the seabed. It scans in the direction it faces, so set it up in or beside the wheelhouse facing forward. It unlocks at skill Tier 15, and the Deep Scan-500 Add-On (Tier 23) fits on its back to show much more of the terrain.
How to Use the Sonar
- Build a Scan-50 Sonar once you reach skill Tier 15.
- Set it in or beside the wheelhouse, facing the way you want to look. It only scans in the direction it faces.
- Watch the screen as you sail: the seabed shows in green and anything worth a look, from ore to a hidden room, shows as a +.
- Every + looks the same, so stop and dive down to see what it is.
- At Tier 23, drop a Deep Scan-500 Add-On behind the sonar; it snaps onto the back and the screen shows much more of the terrain.
What the Sonar Shows
The screen shows the seabed in green and marks ores and other objects with a + sign. In the official screenshot the unit reads BASICSCAN-50 and the screen says "Scan range: 50 m".
It also picks up things below the seabed, such as hidden rooms under a location.
The screen has no key or legend: every object shows as the same + sign.
Update 02 added the sonar module, which scans the ocean floor for resources, including the new ore.
Mine the ores you find with the dismantle tool; the ores and mining guide lists what each one gives.
Where to Put the Sonar
The sonar scans in the direction it faces, ahead and down, not all around the boat.
Set it up in or beside the wheelhouse so you can see it while steering, facing the way you want to look. You can also build two or three, facing forward, left and right.
How to Unlock and Build It
Scan-50 Sonar
Unlocks at skill Tier 15 · 5 electricity to craft
- 2 Alloy Frame
- 1 Battery Cell
- 1 Display Screen
- 1 Connector Ports
- 1 Logic Chip
- 1 Data Storage Chip
- 1 Power Core
Deep Scan-500 Add-On
Unlocks at skill Tier 23 · 5 electricity to craft
- 1 Advanced Alloy Mesh
- 1 Reactive Core
Sonar Materials Calculator
Choose how many sonars to build. The list breaks every part down to the raw materials you need to collect, and adds up the crafts and electricity.
- Crafts
- 12
- Electricity to craft
- 60
- Skill tier needed
- Tier 23
| Material | Amount |
|---|---|
| Aluminium | 12 |
| Titanium | 8 |
| Copper | 7 |
| Plastic | 7 |
| Iron | 6 |
| Glass | 4 |
| Fabric | 3 |
| Gold | 2 |
| Polyurethane | 2 |
| Silicon | 2 |
| Quantum Crystal | 1 |
| Rubber | 1 |
| Part | Amount |
|---|---|
| Alloy Frame | 2 |
| Battery Cell | 1 |
| Display Screen | 1 |
| Connector Ports | 1 |
| Logic Chip | 1 |
| Data Storage Chip | 1 |
| Power Core | 1 |
| Advanced Alloy Mesh | 1 |
| Reactive Core | 1 |
Each craft needs 5 electricity (the wiki lists 5 Wh). For Plastic, Glass, Fabric and the other materials without a link, see what to take apart in the dismantle tool guide.
Plan the points for Tier 15 and Tier 23 in the Skill Planner.
The Deep Scan-500 Add-On
Fit the Deep Scan-500 Add-On to the back of the Scan-50 Sonar. Drop it behind the sonar and it snaps into place.
With the add-on the sonar shows much more of the terrain, including deep places that are hard to reach.
What You Can Find With It
Use it to spot hidden places under the sea, such as seed vaults and seed pods, while sailing past.
Compare what you spot with the coordinates on the interactive map, and see the underwater caves guide before you dive.
Not confirmed yet
The Scan-50 Sonar may weigh 200 kg, and it takes up a lot of room on the boat; the Deep Scan-500 Add-On may weigh 10 kg.
The screen gives no depth reading.
+ marks can move and disappear while the boat is stopped; they may be fish.
The Deep Scan-500 can be found in a hidden room; after restarting the game it showed as ready to learn in the skills menu.
The sonar makes the quest location Mother easier to find under the sea. Mother quest steps
With the Deep Scan-500 Add-On the scan range may reach 500 m, as its name suggests.
Stop about 100 m from a place, facing it, and the screen shows the seabed and the legs of the structure going down.
Mounted on the cabin ceiling facing down, it shows the area under the boat instead of ahead.
Set flat against the back wall of the cabin, the Deep Scan-500 on its back pokes through the wall.
In April 2026 the sonar stopped working tens of seconds after a save was loaded.
Sonar FAQ
How do you use the sonar in The Last Caretaker?
Build the Scan-50 Sonar (skill Tier 15) and set it in or beside the wheelhouse, facing forward. Watch its screen while you sail: the seabed shows in green and anything worth a look shows as a +. Every + looks the same, so stop and dive to see what it is.
How does the sonar work in The Last Caretaker?
The Scan-50 Sonar shows the seabed in green and marks ores and other objects with a + sign, up to a 50 m scan range in the official screenshot. It scans in the direction it faces, ahead and down, and it also picks up things below the seabed.
Where should you put the sonar on your boat?
In or beside the wheelhouse, facing the way you want to look, so you can watch it while steering. It scans in the direction it faces, so you can build two or three facing forward, left and right.
How do you unlock the sonar?
The Scan-50 Sonar unlocks at skill Tier 15 and needs 2 Alloy Frames, a Battery Cell, a Display Screen, Connector Ports, a Logic Chip, a Data Storage Chip and a Power Core. The Deep Scan-500 Add-On unlocks at Tier 23 and needs an Advanced Alloy Mesh and a Reactive Core.
How do you use the Deep Scan-500 add-on?
Fit it to the back of the Scan-50 Sonar: drop it behind the sonar and it snaps into place. The sonar then shows much more of the terrain.
What do the + signs on the sonar mean?
They mark ores and other objects. The screen has no key, so every object looks the same until you go and look.
Does the sonar scan all around the boat?
No. It scans in the direction it faces, ahead and down. Turn it toward what you want to see, or build two or three facing forward, left and right.
What does the Deep Scan-500 add-on do?
It fits on the back of the Scan-50 Sonar and lets it see further below the seabed: the screen shows much more of the terrain, including hidden spaces and deep places that are hard to reach. It unlocks at Tier 23.
What materials do you need to build a sonar?
A Scan-50 Sonar needs 7 Copper, 7 Plastic, 5 Iron, 4 Aluminium, 4 Glass, 3 Fabric, 3 Titanium, 2 Gold, 2 Polyurethane, 2 Silicon, 1 Rubber, made into its parts at the Fabricator: 9 crafts in all. The Deep Scan-500 Add-On adds 8 Aluminium, 5 Titanium, 1 Iron, 1 Quantum Crystal and 3 more crafts.
