Best Upgrades Guide for Subnautica 2: Complete Tier List

Understanding Upgrades in Subnautica 2

So you've been playing for a bit and you're wondering what to upgrade. Fair — there's a LOT of stuff to unlock and some of it is definitely not worth your time. After 200+ hours, here's what I've learned.

Most upgrades you craft at the Fabricator, then slot them into your equipment or vehicle. Some stack, some don't. The ones that don't? Pick carefully — slots are limited.

Rare materials take forever to get. Kyanite, Magnetite, the good stuff. Don't waste it on garbage upgrades. This guide's here so you don't have to learn that the hard way like I did.

Upgrade Categories

Three main categories: Personal Equipment (oxygen, speed, protection), Vehicle Upgrades (Seamoth, Prawn Suit, Cyclops), and Base Upgrades (power, production, storage).

Personal stuff comes online first — basic materials, quick to get. Vehicles need deeper exploration and rarer resources. Bases are somewhere in between.

S-Tier: Essential Upgrades

If you're only gonna grind for a few upgrades, these are them. They're not optional — they're the difference between struggling and actually enjoying the game.

1. Ultra High Capacity Tank

This is THE upgrade. 45 oxygen isn't enough once you start going deep — trust me, I've blacked out more times than I can count. The Ultra High Capacity Tank more than doubles your air. Suddenly dives that seemed impossible are totally doable.

Downside? It needs Kyanite. Kyanite's in the deep. Like, really deep. Getting it is the early-game challenge that separates the patients from the quitters. Push through — it's worth it.

2. Cyclops Bridge Upgrades

The Cyclops is your endgame mobile base. The bridge upgrades make it actually usable. Thermal Reactor = free power from vents. Sonar = spot threats before they spot you. Engine Efficiency = way longer range.

A fully upgraded Cyclops is basically a base that follows you around. Once you've got one kitted out, you can basically live out of it. Game changer, fr.

3. Prawn Suit Drill Arm

Mining mineral nodes by hand is painful. The Drill Arm makes it fast. Point, drill, done. Also damages creatures if things get spicy.

Combined with the grapple arm, your Prawn Suit handles both mining AND combat. Late-game ore deposits? Basically impossible without this. Don't sleep on it.

4. Stasis Rifle

Freezes creatures in place. No damage, just time. Against a Reaper? That time = your life. Even against smaller aggressive creatures, freezing them lets you scan or harvest without the danger.

You don't NEED it if you're careful, but when something goes wrong — and it will — you'll be really glad you have it. Always bring it to Leviathan areas.

A-Tier: Highly Recommended

Not essential, but they make life so much easier. Get these once your S-tier upgrades are handled.

5. Seamoth Depth Modules

The Seamoth is your workhorse early-to-mid game. Depth modules let it go deeper. Each one = more crush depth = more areas accessible.

Get these as soon as you have materials. The Seamoth's speed and maneuverability make it better than the Prawn Suit for most exploration stuff, even after you get the bigger vehicle.

6. Thermal Power Module

Power management is annoying. Thermal Power Module fixes that — it harvests heat from vents and generates free power. No more constant battery swaps.

In bases, thermal generators provide baseline power that charges batteries automatically. In the Cyclops? Game changer for long operations. Find thermal vents, document them, profit.

7. Ultra Capacity Battery

Doubles your energy storage. Less charging, more doing. When combined with good power generation, you can basically operate forever without worrying about it.

Get this once you've got stable resource gathering going. It's not urgent but it's super nice to have.

8. Storage Expansion Modules

Inventory space is ALWAYS a problem. Seamoth storage module, Prawn Suit storage module, base lockers — more slots = fewer trips = better gameplay.

Prawn Suit storage is bigger and essential for mining ops. Don't skip this one.

B-Tier: Useful When Available

These upgrades provide valuable benefits but are either situational or provide incremental improvements that can be safely deprioritized in favor of higher-tier options. Acquire these when you have spare resources or specific needs that they address.

9. Radiation Suit Modules

In areas affected by radiation, standard equipment degrades rapidly. Radiation suit modules for both vehicles and personal equipment extend your operational time in these hostile zones before suffering damage. While not universally applicable, they are essential for any serious exploration of radioactive regions.

The Alien Thermal Plant and certain story-related areas contain significant radiation hazards. Without proper protection, you will take continuous damage and your equipment will deteriorate. Plan your radiation protection based on your intended activities, and acquire the necessary modules before attempting to explore radioactive zones.

10. Vehicle Armor Plating

Armor plating for your vehicles reduces damage from collisions and creature attacks. While this does not make your vehicles invulnerable, it extends their operational lifespan in dangerous environments and provides a margin of safety for less experienced pilots.

11. High Capacity Air Filtration

For base installations in deep water, air filtration becomes a concern. The High Capacity Air Filtration module ensures your base always has clean, breathable atmosphere even when sealed for extended periods. This is more of a convenience upgrade than a necessity, but it provides peace of mind during extended operations.

Vehicle-Specific Upgrades

Each vehicle has its own upgrade path. Here's how to build each one right.

Seamoth Upgrade Path

Speed, depth, efficiency. That's the Seamoth. Torpedo for self-defense, Sonar to spot stuff at range, Electrical Defense against aggressive creatures.

Most people: prioritize depth, storage, efficiency. That maximizes what the Seamoth's good at. Combat stuff can wait until you actually need it.

Prawn Suit Upgrade Path

This thing's a beast. Drill Arm and Grappling Arm are basically mandatory. Jump Jet Enhancement fixes its main weakness — mobility.

Thermal Reactor extends operation time. Torpedo Arm for combat when drill isn't practical. Build it around what you're doing most.

Cyclops Upgrade Path

Mobile base. Bridge upgrades first (Thermal, Sonar, Engine Efficiency), then shields. Once kitted out, you can basically live in it.

Fully upgraded Cyclops = your main base for most of the game. Worth the investment.

Base Module Upgrades

Bases become more than just shelter once you kit them out. Here's what matters.

Power Generation Modules

Solar Panels: easy, works off sunlight. Battery Modules: store extra power for nighttime. Nuclear Reactor: insane output but needs Uranium — endgame stuff.

Thermal Generators from vents give consistent power day or night. Multiple thermal generators can run even big bases indefinitely. Better than solar for permanent spots.

Production Modules

Bio-Reactor: turns excess food and creature stuff into power. Water Filtration System: makes drinkable water automatically. Fabricator Upgrade Module: unlocks advanced crafting.

Aquariums hold creatures for decoration, research, or resources. Growbeds enable large-scale plant farming. Modification Station: unlocks advanced upgrades.

Upgrade Priority Strategy

How you approach your upgrade progression significantly impacts your gameplay experience. A well-planned strategy ensures you always have the capabilities you need while avoiding wasted resources.

Early Game Priorities

In the early game, focus on basic quality-of-life upgrades that improve your survival capabilities. Oxygen tank upgrades should be your first priority, followed by basic storage expansions. The Survival Knife should be enhanced early, and you should acquire the scanner tool as soon as possible to begin unlocking blueprints.

Seamoth depth modules become valuable as soon as you have materials to craft them. Even the first depth module significantly expands your accessible area. Prioritize establishing a reliable resource gathering route for titanium, copper, and lead, as these materials form the foundation of early upgrades.

Mid Game Focus

Mid game is when vehicle upgrades become critical. Acquire your Prawn Suit and begin upgrading it for mining operations. The Cyclops should be obtained and basic upgrades installed. Base building should expand significantly, with dedicated facilities for power generation, food production, and advanced crafting.

This is also when you should begin serious exploration of deeper biomes to acquire rare materials. Kyanite, magnetite, and crystalline sulfur become increasingly important. Establish forward operating bases to reduce travel time to deep resource locations.

Late Game Optimization

Late game upgrades focus on optimization and convenience. Complete your vehicle upgrade paths and ensure your base has sustainable power and food production. The remaining upgrades are primarily quality-of-life improvements that make your already capable setup even more efficient.

Consider building a dedicated upgrade testing facility where you can experiment with different configurations. Some upgrades have unexpected synergies or drawbacks that are not immediately obvious from their descriptions.

Common Upgrade Mistakes

Learning from common upgrade mistakes saves resources and frustration. Understanding what not to do is as important as knowing what to prioritize.

Mistake 1: Spreading Resources Too Thin

Resisting the temptation to upgrade everything is crucial. Resources are limited, and upgrading everything means upgrading nothing well. Focus on completing one upgrade category before moving to the next. A fully upgraded Seamoth is more valuable than a partially upgraded Seamoth, Prawn Suit, and Cyclops.

Mistake 2: Ignoring Storage

Many players neglect storage upgrades until they are constantly running out of inventory space. By then, they have wasted significant time making multiple trips. Prioritize storage upgrades before you feel the pressure, and you will save time overall.

Mistake 3: Wrong Upgrade Order

Some upgrades are prerequisites for others. Acquiring upgrades out of order can result in wasted resources if you later need to replace them with improved versions. Research upgrade trees before investing significant resources.

Mistake 4: Neglecting Power Infrastructure

Upgrading equipment that requires power without first ensuring reliable power generation leads to constant frustration. Your base and vehicles will spend more time charging than operating. Build robust power infrastructure before upgrading power-hungry systems.

Final Thoughts

The upgrade system in Subnautica 2 provides almost unlimited customization options, but not all upgrades are created equal. This tier list provides a roadmap for maximizing your efficiency, but every player's experience is unique. Adjust your upgrade priorities based on your play style and immediate needs.

Remember that the best upgrade is the one that addresses your current challenge. Sometimes a B-tier upgrade that solves an immediate problem is worth more than an S-tier upgrade that helps with theoretical future scenarios. Stay flexible, plan ahead, and enjoy the journey of building the perfect survival loadout.