Staying hydrated in Subnautica is a survival mechanic that requires frequent attention, especially at the beginning of the game when there are few options for getting or making water. This guide explores all of the water sources available in Subnautica from early to late game.
Early Game Options for Getting Water in Subnautica
Most players who start a new game of Subnautica find themselves frantically trying to figure out how to get water, as the hydration bar rapidly depletes and there is no obvious explanation of how to make water.
Make Filtered Water from Bladderfish
Your best option for getting water early game is to catch Bladderfish, and then use the Fabricator in your Lifepod or Seabase to convert each of them into a bottle of Filtered Water. Each Filtered Water provides only +20 H2O, making it the lowest-tier water bottle in the game.
Bladderfish can be a hassle to constantly find and catch. Setting up a Grav Trap near your Lifepod or Seabase can help ease this chore. Better yet, experiment with setting up 2 or more Grav Traps spaced just far enough apart to keep captured fish nearly immobilized.
Make Disinfected Water from Salt Deposits and Coral Tube Samples
Disinfected Water provides +30 H2O per bottle, a 50% improvement over Filtered Water. As soon as you start exploring beyond the Safe Shallows into the Kelp Forest and Grassy Plateaus biomes you’ll start to find Salt Deposits on the seabed. At the Fabricator these can be combined with Coral Tube Samples, which are gathered by striking the Giant Tube Corals in the Safe Shallows with the Survival Knife, to fabricate Bleach. Each Bleach can then be converted again, using the Fabricator, into two Disinfected Waters for a total of +60 H2O per Salt Deposit that is gathered.
Eat Cooked Fish
In addition to refilling your Food bar, any cooked fish that you eat also provide a small amount of water. This amount ranges from +3 to +10 H2O depending on the species of fish.
Eat Creepvine Samples
This method is a last resort but can save your life if you happen to be desperate for hydration too far from home to make water, but close to a Kelp Forest biome. Each Creepvine Sample provides only +1 H2O. They are tedious to gather, take up an enormous 4 stacks/squares of inventory space, and each vine will disappear after several samples are cut from it using the Survival Knife. They must be eaten immediately as they rot very quickly.
For those attempting to play through the game vegan (which is possible though challenging,) Creepvine Samples can be a handy source of water early game.
Mid-Game Hydration Options
Although the constant need for hydration never decreases, your options for getting water fortunately get more convenient as you progress through the game. The two big game-changers
Stay Hydrated at Home with Farm-able Plants
Once you have made a trip out to the Floating Island, you’ll be able to grow edible plants inside (or even outside) of your Seabase. These plants provide not only a source of food but also of water, to varying degrees. Marblemelon and Bulbo Tree are both excellent water sources, but Bulbo Trees tend to require less maintenance in terms of replanting. To collect the edible Bulbo Tree Samples, strike a Bulbo Tree with the Survival Knife.
Like the Creepvine Samples, the food harvested from edible plants will spoil in minutes so it’s only useful for refilling your food and H2O levels while you’re at your Seabase. You’ll still want to bring bottled water with you for missions away from home. Still, this makes it much easier to accumulate bottled water since much of your time will be spent in and around your Seabase. You can also set up small remote Seabases with food farms inside to help supplement your usage further from home.
The Water Filtration Machine
Once you’ve acquired the blueprint for the Water Filtration Machine, you can produce Large Filtered Water, the highest-quality water bottles available in the game with +50 H2O each. The only real downside is that in order to operate this machine your Seabase needs to consume quite a bit of energy.
Late Game Hydration Options
The final upgrade to water production is the Stillsuit, which, when worn, produces Reclaimed Water in the player’s inventory every so often. The blueprint for the Stillsuit is found in wreckage in some of the more dangerous areas of the game (Bulb Zone, Dunes, and Mountains biomes.) The Reclaimed Water produced by the Stillsuit provides +20 H2O, but costs -3 Food.