Hunger and thirst are the two constants that never stop ticking in Subnautica 2. Whether you are building your first base in the Safe Shallows or exploring the lava-blasted depths of the Lava Zone, you must eat and drink. Neglect either meter and your max health drops, your movement speed decreases, and eventually you die. This guide covers every food and water source, the most efficient farming methods, storage solutions, consumption rate math, and emergency strategies.
How Hunger and Thirst Work
Subnautica 2 tracks two separate survival meters: Food and Water. Both deplete over real time regardless of what you are doing. Swimming fast, taking damage, and fighting all increase consumption rates slightly, but the base depletion is constant.
- Food bar: 100 points. Depletes at ~1 point per 48 seconds (~80 minutes from full to empty).
- Water bar: 100 points. Depletes at ~1 point per 40 seconds (~67 minutes from full to empty).
Water depletes roughly 20% faster than food. When either bar drops below 20%, your max health is reduced by 25% and swim speed drops by 15%. When either bar hits zero, you lose 1 health per second until you eat or drink.
At zero food or water, you lose 1 HP per second. With 100 base HP, you have 100 seconds to find supplies before you die. Always carry at least one food item and one water bottle at all times.
All Food Sources
| Food Item | Food Value | Water Value | Source | Farmable |
|---|---|---|---|---|
| Boomerang (raw) | 12 | 0 | Safe Shallows | No |
| Boomerang (cooked) | 23 | +5 | Fabricator | No |
| Hoverfish (raw) | 16 | 0 | Kelp Forest | No |
| Hoverfish (cooked) | 32 | +5 | Fabricator | No |
| Reginald (raw) | 20 | 0 | Grassy Plateaus | No |
| Reginald (cooked) | 40 | +8 | Fabricator | No |
| Spadefish (raw) | 14 | 0 | Safe Shallows | No |
| Spadefish (cooked) | 28 | +5 | Fabricator | No |
| Eye Eye (raw) | 18 | 0 | Kelp Forest caves | No |
| Eye Eye (cooked) | 36 | +6 | Fabricator | No |
| Hoopfish (raw) | 10 | 0 | Safe Shallows | No |
| Hoopfish (cooked) | 20 | +4 | Fabricator | No |
| Melon | 18 | +6 | Indoor Planter | Yes |
| Chinese Potato (raw) | 12 | +3 | Outdoor Planter | Yes |
| Chinese Potato (cooked) | 24 | +8 | Fabricator | Yes |
| Creepvine Cluster (cooked) | 15 | +10 | Fabricator | Yes |
Always cook your fish. Cooking roughly doubles food value and adds a small water bonus. The downside is cooked fish spoils after ~45 minutes. Raw fish does not spoil, so only cook what you will eat within 30 minutes.
All Water Sources
| Water Source | Water Value | Food Value | Method | Sustainability |
|---|---|---|---|---|
| Disinfected Water | 40 | 0 | Fabricator (2 Bladderfish) | Medium |
| Large Filtered Water | 50 | 0 | Water Filtration Machine | High (automated) |
| Bleach | 30 (3 drinks) | -15 | Fabricator (4 Creepvine + 2 Salt) | Emergency only |
| Cooked fish | +4 to +8 | Varies | Fabricator | Supplemental |
| Melon | +6 | 18 | Grown in planter | High (renewable) |
| Chinese Potato (cooked) | +8 | 24 | Grown + cooked | High (renewable) |
Disinfected Water
Crafted at the Fabricator using 2 Bladderfish, each bottle provides 40 water. One bottle lasts ~27 minutes. You need about 2.5 bottles per hour.
Water Filtration Machine
The key to sustainable water supply. It automatically produces Large Filtered Water (50 water) and Salt. Produces one water every 15 minutes (200 water/hour) — enough to sustain 3 players.
Build two Water Filtration Machines and alternate them. Running both simultaneously draws 100 epm. Run one until it produces 3–4 waters, then switch to the second. This halves power consumption while maintaining the same production rate.
Bleach
Emergency only. Crafted from 4 Creepvine Samples + 2 Salt. Provides 3 drinks of 10 water each (30 total), but each drink costs 5 health.
Sustainable Farming Methods
Indoor Planter Farm (Melons)
Each planter holds 4 Melon plants. Each produces 1 Melon every 8 minutes up to 3 max per plant. Stops producing until harvested.
- Per planter: 12 Melons max = 216 food + 72 water
- One planter covers food for ~2.9 hours, water for ~48 minutes.
- Two planters cover food for ~5.8 hours, water for ~1.6 hours.
Outdoor Planter Farm (Chinese Potatoes)
Chinese Potatoes take 10 minutes to grow, max 3 per plant. Cooked: 24 food + 8 water — the most water-efficient farmed food item.
| Crop | Growth Time | Max/Slot | Food/Water (raw) | Food/Water (cooked) | Best Use |
|---|---|---|---|---|---|
| Melon | 8 min | 3 | 18 / +6 | N/A | Primary food + water |
| Chinese Potato | 10 min | 3 | 12 / +3 | 24 / +8 | Best water ratio cooked |
| Creepvine | 6 min | 2 | N/A | 15 / +10 | Water + Bleach material |
Optimal Farm Layout
- 2 Indoor Planters (16 plants) — 48 Melons at capacity (864 food + 288 water, 11+ hours of food)
- 1 Water Filtration Machine — 200 water/hour, covers the 90 water/hour consumption
- 1 Outdoor Planter with Chinese Potatoes — Supplemental water and alternative food
Harvest proactively, not reactively. Plants stop growing at maximum yield. Check your farm every 15–20 minutes and harvest everything to keep the cycle active.
Storage Solutions
Build dedicated Wall Lockers near your farm and filtration machine. Label by category. Each locker holds 16 items; a column of 4 holds 64 items — enough for a multi-hour buffer.
Expedition Loadout
For 30+ minute trips from base, pack:
- 2 Large Filtered Water (100 water — 67 minutes)
- 3 Cooked Reginalds (120 food — 96 minutes)
- 2 Disinfected Water (80 water backup)
- 1 cooked Hoopfish (20 food emergency)
This uses 8 slots and provides ~1.5 hours of food and 2 hours of water.
Consumption Rate Math
| Metric | Per Hour | Per 2 Hours | Per 4 Hours |
|---|---|---|---|
| Food consumed | 75 pts | 150 pts | 300 pts |
| Water consumed | 90 pts | 180 pts | 360 pts |
| Cooked Reginalds needed | 2 | 4 | 8 |
| Large Filtered Water needed | 2 | 4 | 8 |
| Melons needed | 5 | 9 | 17 |
Emergency Survival Strategies
Near Surface (0–100m)
- Catch Bladderfish — 2 fish for immediate Disinfected Water.
- Catch any small fish — Eat raw to stop health drain (10–20 food).
- Collect Creepvine — Craft Bleach if you have Salt.
Deep Zones (200m+)
Never descend below 200m without 2 Large Filtered Water and 2 cooked fish. No food or water exists in deep biomes. If supplies run out at 800m, your only option is an emergency ascent through dangerous creature territory.
If caught deep without supplies:
- Check for Reginalds in Grassy Plateaus (100–200m) during ascent.
- Use Seaglide to ascend as fast as possible.
- Use Medkits to buy time (50 HP = 50 extra seconds).
- Drop heavy loot to swim faster.
Consumption Optimization Tips
- Stay inside your base when idle. Consumption pauses in a powered base.
- Time your meals. Wait until bars drop to 30–40% before eating.
- Use vehicles for transit. Fast swimming increases consumption by ~10%.
The "big meal" strategy is more inventory-efficient. One cooked Reginald (40 food, 1 slot) beats four Hoopfish (80 food, 4 slots) when spoilage is factored in. Pack cooked Reginalds for long expeditions.
Summary: Golden Rules
- Always carry emergency supplies. 2 water + 2 food minimum.
- Cook fish for double value, but only what you will eat soon.
- Build a Water Filtration Machine early.
- Set up melon farming for renewable food.
- Harvest proactively. Maxed-out plants stop growing.
- Never go deep without supplies.
- Time your meals to minimize waste.
Mastering food and water management transforms Subnautica 2 from a constant survival struggle into an adventure where you choose when to explore. Set up your farm, keep filtration machines running, and pack smart. Stay fed, stay hydrated, diver.