Subnautica 2 Seafloor Mapping: How to Map the Ocean Floor

Seafloor Mapping Basics

Mapping the seafloor in Subnautica 2 is one of the most rewarding long-term projects you can undertake. Unlike the first game, the sequel features a much larger and more vertically complex ocean, which means a reliable mental map (and a network of markers) is essential for survival. The core idea is simple: you travel across the seabed, drop beacons at key landmarks, and mentally stitch together the geography so you always know how to get home.

Start by understanding that the game does not give you a traditional minimap. Instead, you rely on a combination of the compass, beacons, and your own observations. The lifepod serves as your origin point, and every direction you swim from it should be tracked. A good habit is to always note which compass direction you are heading before you leave a safe zone.

The seabed is divided into biomes, and each biome has a distinct visual identity. Sand, kelp, rock spires, glowing flora, and wreckage all serve as landmarks. When you map, you are really cataloging the relationship between these biomes. Draw your own sketch on paper if it helps, because the in-game tools are limited by design.

• Always carry at least three spare beacons when exploring.
• Note the depth of each new area you discover.
• Use the scanner to identify resources, which helps confirm which biome you are in.
• Listen for ambient audio cues that signal biome transitions.

Essential Mapping Tools and Equipment

To map the ocean floor effectively you need the right tools. The most important is the beacon, a cheap craftable marker that floats in place and broadcasts a labeled signal to your HUD. You should craft beacons as early as possible and treat them as disposable breadcrumbs. The recipe typically requires copper wire and a battery, so stock up on copper ore before you begin a serious mapping expedition.

The compass is your second critical tool. It attaches to your HUD once crafted and lets you read exact cardinal directions. Without it you are effectively guessing, because the underwater environment can be disorienting, especially in foggy or dark biomes. Pair the compass with the survival knife, which lets you clear kelp and collect samples that help you identify where you are.

Once you unlock the Seamoth, mapping becomes far easier because you can cover large distances quickly and carry a oxygen supply. The Seamoth also has a built-in depth display and compass. Later, the scanner room becomes the most powerful mapping tool of all: it can scan a large radius around your base and reveal resource nodes, wrecks, and even creature locations on a holographic display.

Mapping by Depth Zones

The Subnautica 2 ocean is organized into depth zones, and understanding these zones is the key to mapping efficiently. The shallow safe shallows near your lifepod are the starting zone, typically zero to fifty meters deep. Below that you enter the kelp forests and grassy plateaus, which range from roughly fifty to two hundred meters. Deeper still are the deep zones and cave networks that plunge past five hundred meters.

Each depth zone has a unique set of resources and dangers, so your map should record not just horizontal position but also vertical range. When you discover a new biome, note the depth at which it begins and ends. This helps you plan dives and avoid accidentally swimming into a predator-heavy zone without enough oxygen.

Oxygen management is tied directly to depth. The deeper you go, the less time you have before you must surface. A high-capacity oxygen tank lets you map deeper zones, while a Seamoth or habitat let you establish relay stations. Mapping depth zones also helps you locate the transition points where rare resources appear, because many materials only spawn below a certain depth threshold.

• Shallows: 0-50m, safe, basic resources.
• Kelp/Plateaus: 50-200m, moderate danger, mid-tier ore.
• Deep zones: 200-500m+, high danger, rare materials.
• Caves: variable depth, unique loot, hostile fauna.

Advanced Mapping Tips and Workflow

Once you have the basics down, you can adopt a systematic workflow that turns chaotic exploration into a clean map. The best approach is to map in grid sweeps: pick a compass heading, swim straight along that heading for a set distance, drop a beacon, then move one lane over and sweep back. This ensures full coverage without missing pockets of terrain.

Label your beacons clearly. A beacon named simply 'rock' is useless after you have twenty of them. Use descriptive labels like 'KELP-N-120' or 'WRECK-NE-300' that encode the biome, direction, and depth. This makes your HUD readable at a glance and prevents confusion when multiple beacons overlap on screen.

Build small outpost habitats at major mapping hubs. A single room with a powered hatch and a fabricator gives you a safe oxygen refill point and a place to craft replacement beacons on the fly. This dramatically extends how far you can map in one session. Finally, always map during the day when possible, because the additional light makes terrain features far easier to identify and remember.

Remember that the ocean is dangerous. Never push your oxygen to the last second, and always leave a clear retreat path back to a beacon or your base. A good mapper is a living mapper.