Subnautica: Below Zero Biomes

18 biomes and named areas, each with its depth, what spawns there and the pins inside it. The game's biome map has 23 classes; the table at the bottom says which have a page and why the others do not.

Updated November 2, 2026Data: Subnautica: Below Zero game files (build of 12 Aug 2025), read and drawn by PinDrop. (c) Unknown Worlds Entertainment. PinDrop is fan-made and not affiliated with Unknown Worlds Entertainment.

Map of Subnautica: Below Zero with the biome classes coloured — Open the map, pick a biome to focus →

Subnautica: Below Zero biomes and areas

Arctic Kelp	5 m to 242 m	0.16 km²	62,369	Quartz Boomerang	99
Arctic Spires	+93 m to +16 m	0.61 km²	9,276	Limestone	170
Crystal Caverns	148 m to 842 m	-	77,022	Uraninite crystal Red Feather Fish	4
Delta Island	+59 m to 166 m	0.05 km²	203	Gold Skyray	111
East Iceberg Zone	+67 m to 348 m	0.40 km²	91,965	Limestone Boomerang	95
Fabricator Caverns	637 m to 1119 m	-	27,620	Silver Spinefish	3
Glacial Basin	+68 m to 209 m	0.47 km²	5,113	Quartz Arctic Peeper	477
Glacial Bay	+64 m to 134 m	0.12 km²	17,263	Limestone Eye Jelly	70
Glacial Pass	59 m to 233 m	-	7,297	Limestone Eye Jelly	31
Koppa Mining Site	98 m to 328 m	-	8,852	Silver Rockgrub	114
Lily Pads	+0 m to 692 m	0.60 km²	187,096	Limestone Boomerang	253
Outpost Zero	-	0.04 km²	0		61
Purple Vents	+8 m to 638 m	0.25 km²	47,373	Quartz Feather Fish	134
Sparse Arctic Zone	+43 m to 286 m	0.29 km²	46,236	Quartz Symbiote	21
Thermal Spires	+17 m to 505 m	0.29 km²	58,905	Silver Arctic Peeper	47
Tree Spires	+0 m to 593 m	0.27 km²	105,949	Silver Red Feather Fish	27
Twisty Bridges	+5 m to 393 m	0.27 km²	76,217	Limestone Hoopfish	98
West Iceberg Zone	+66 m to 282 m	0.25 km²	51,927	Limestone Boomerang	122

Spawn numbers are a model read from the game's spawner tables and 921,892 baked slots, not verified in a running game.

The 23 classes of the biome map

The game stores its biomes as a 1,024 by 1,024 grid of 4 m cells with 23 class names. 3 classes are variants of a biome and are merged into its page (Twisty Bridges, Shallow Twisty Bridges, Glacial Basin (underwater)); 7 have no page. Four more pages (Glacial Pass, Crystal Caverns, Fabricator Caverns, Koppa Mining Site) have no class of their own: the grid is flat, so the game keeps those areas only in its spawner tables, and they are named from the game's own location strings.

Biome map classes and their pages
Class	Name in the game	Grid cells	Page
`eastarctic`	East Iceberg Zone	25,069	East Iceberg Zone
`deepArctic`	Deep Arctic	0	No page: 0 raster cells; only 33 baked slots (DeepArctic_*)
`sparseArctic`	Sparse Arctic Zone	18,082	Sparse Arctic Zone
`arcticKelp`	Arctic Kelp	9,898	Arctic Kelp
`arctic2`	Arctic (class 2)	0	No page: 0 raster cells; no slot table of that name
`glacialBasin`	Glacial Basin	28,084	Glacial Basin, the underwater class is merged into it
`twistyBridges`	Twisty Bridges	0	Twisty Bridges, merged into Twisty Bridges (0 raster cells: the deep part exists only in the slot tables)
`twistyBridges_Shallow`	Shallow Twisty Bridges	17,139	Twisty Bridges, merged into Twisty Bridges
`glacier`	Glacier	0	No page: 0 raster cells; 65 baked slots (Glacier_Generic)
`lilyPads`	Lily Pads	37,452	Lily Pads
`thermalSpires`	Thermal Spires	18,377	Thermal Spires
`treeSpires`	Tree Spires	17,141	Tree Spires
`rocketArea`	Delta Island	3,099	Delta Island
`purpleVents`	Purple Vents	15,805	Purple Vents
`hoverZone3`	Hover Zone 3	0	No page: 0 raster cells and no baked slots
`startZone`	Outpost Zero	2,829	Outpost Zero
`tundraVoid`	Tundra void	471,583	No page: the void outside the map: no slots, no pins
`waterVoid`	The Void	287,359	No page: open water outside the map (The Void): no slots
`arcticSpires`	Arctic Spires	38,344	Arctic Spires
`worldEdge`	World Edge	33,694	No page: the map's boundary band: ground slots only (WorldEdge_Ground), no named places
`glacialBay`	Glacial Bay	7,454	Glacial Bay
`glacialBasin_Underwater`	Glacial Basin (underwater)	1,463	Glacial Basin, merged into Glacial Basin
`westArctic`	West Iceberg Zone	15,704	West Iceberg Zone

Spawner areas with no page of their own: WorldEdge (14,080 slots), MargArea (9,627 slots), IceSheet (7,128 slots), Arctic (3,998 slots), ArcticCaldera (3,844 slots), MethaneIceCave (2,409 slots), Glacier (65 slots), DeepArctic (33 slots), HotSprings (25 slots). They are counted in the resource and creature totals as “Other areas”.

How the biome pages are built

Depth of an area = the heights of its baked slots (min, 5th, median, 95th percentile, max). A pin belongs to the area of the nearest baked slot within 30 m (3-D, so a cave counts for its own area); a pin with no slot nearby takes the biome-map class above it (2-D). Depth is metres below sea level; the Arctic Spires and Outpost Zero lie above it.

“Most likely here” is the resource and the creature with the largest expected count in the area. Both are a model of the game's spawner tables, not verified in a running game; pins are exact. See the creatures, flora and resources pages.

Biome names are the game's own location strings. The map's biome focus draws the border of a class on the full map.