Where to Find Diamonds in Subnautica Below Zero
Diamonds are one of the most sought-after resources in Subnautica: Below Zero, and for good reason — they're essential for crafting some of the game's most powerful tools and upgrades. If you've been searching the shallow waters and coming up empty, that's because diamonds don't play by the same rules as more common minerals. Knowing where to look, and how deep you'll need to go, makes all the difference.
What Are Diamonds Used For in Subnautica Below Zero?
Before diving into locations, it helps to understand why diamonds matter. In Below Zero, diamonds are a tier-2 crafting material used in several critical recipes, including:
- Aerogel (required for advanced thermal insulation upgrades)
- Laser Cutter (essential for accessing locked doors and wrecks)
- Hardened Blade (an upgraded melee tool)
- Reinforced Dive Suit (increases depth and temperature tolerance)
The laser cutter in particular is a progression gate — without it, large portions of the map stay locked off. That makes finding diamonds early a meaningful priority, not just a side objective.
The Key Variables That Affect Your Diamond Search
Not every playthrough looks the same. A few factors shape where diamonds will be most accessible for you:
- Progression stage — early game players won't have vehicles that reach diamond-rich depths
- Vehicle availability — a Seatruck with a depth module dramatically opens up your search radius
- Biome familiarity — some diamond-rich zones are visually distinctive; others require active scanning
- Whether you've found the Alterra Supply Fragments — some crafted tools make resource gathering faster
These variables mean there's no single "best" location that works equally for every player.
Primary Locations Where Diamonds Spawn 💎
Koppa Mining Site
This is the most reliable early-to-mid game diamond source. The Koppa Mining Site is an underwater cave system located beneath the Delta Island interior and accessible from the water. Diamonds appear as blue crystalline outcroppings on cave walls and floors throughout this area. Because it's a purpose-built mining zone in the game's lore, resource density here is notably higher than in open biomes.
Access requires either swimming or a Seatruck. The site is moderately deep, so watch your oxygen and temperature gauges.
Thermal Spires
The Thermal Spires biome sits at roughly 150–200 meters depth and features geothermal activity that correlates with higher mineral density. Diamond outcroppings appear on rock formations near the spire bases. This biome also provides passive heat exposure, which ties in with why insulation upgrades — crafted partly from diamonds — matter.
Navigating here without a Seatruck depth upgrade is possible but risky; pressure warnings will appear without the right modules.
Crystal Caves
The Crystal Caves biome is a mid-to-late game zone sitting at 400+ meters depth. It's one of the most visually striking areas in the game and also one of the most diamond-dense. The entire environment is built around crystalline formations, and diamonds can be found embedded in large clusters.
Reaching Crystal Caves requires a fully depth-upgraded Seatruck or Prawn Suit. Attempting this biome underprepared — especially without cold protection and adequate oxygen planning — is a common mistake. The payoff in diamonds (and other rare materials) is significant if you're equipped for it.
Deep Twisty Bridges
The Deep Twisty Bridges extends the standard Twisty Bridges biome further down. Diamonds appear here with moderate frequency, and the biome is more accessible than Crystal Caves, making it a reasonable mid-game target. The geometry of the area — winding rock formations and overhangs — means diamonds are often tucked into less obvious spots rather than sitting in open view.
Lilypad Islands (Deeper Sections)
The lower reaches of the Lilypad Islands biome also produce diamonds, particularly around rock outcroppings beneath the floating lily structures. This location is sometimes overlooked because the upper sections of the biome feel shallow and resource-light. The deeper floor tells a different story.
Practical Tips for Efficient Diamond Farming
| Factor | What to Know |
|---|---|
| Visual ID | Diamonds appear as blue-white angular crystals — distinct from quartz, which is lighter and smoother |
| Scanning | Using a Scanner Room with range/speed upgrades marks resources automatically on your HUD |
| Depth prep | Most reliable diamond biomes sit below 150m — depth modules are not optional for consistent farming |
| Cold exposure | Many diamond zones overlap with cold biomes — insulation upgrades reduce passive health drain |
| Vehicle choice | Prawn Suit drill arm speeds up harvesting from large outcroppings significantly |
The Scanner Room deserves special mention. Placing one near Koppa Mining Site or at a Thermal Spires base and equipping it with Camera Drones lets you map diamond deposits across a wide radius without manually swimming every tunnel.
How Depth and Progression Shape Your Options
Early in the game — before you have depth modules or a Seatruck — diamond access is genuinely limited. Koppa Mining Site is the practical first target because it's reachable on lung capacity or with a basic Seatruck configuration.
Mid-game players with a depth-upgraded Seatruck unlock Thermal Spires and Deep Twisty Bridges as viable farming zones. Late-game players with full vehicle upgrades can access Crystal Caves at volume.
This tiered availability is intentional game design — diamonds gate certain crafting recipes that would otherwise trivialize early survival mechanics. Where you are in that progression determines which of these locations is actually useful to you right now, and which ones are worth planning toward as your next upgrade milestone.