Each of Subnautica’s biomes is beautiful and unique, with distinct features and secrets to explore. One of the most unique biomes in the game is the Lost River. This biome is filled with treasures, wondrous sights, and hidden secrets that tell the tale of Planet 4546B’s past. Players must visit the Lost River to uncover what lies amidst the mist in the very depths of the planet.
How to Find the Lost River in Subnautica
Before you embark on your journey in search of the Lost River, you must prepare the right equipment first. As it is a far and dangerous journey, you must be well-equipped to get back home safely.
The first thing you should prioritize is your means of transportation. The Lost River is located in the planet’s depths, far from the surface. You will need a sufficient portable oxygen source and the right suit for deep-sea diving. On a regular scout mission, you can simply use a Seamoth with the Depth Module MK3 upgrade equipped. As the Lost River’s depth exceeds 500m, using a Depth Module MK2 is insufficient.
But if you plan to traverse the Lost River, it is advised to use a well-upgraded Cyclops. Your Cyclops should have a Sonar and a Depth Module MK1 upgrade. Ideally, you can bring a Prawn Suit equipped with a drill arm in your Cyclops. This will allow you to efficiently explore the Lost River while gathering resources.
The next thing you should prepare is your expedition equipment. This includes all the supplies you will need to survive the journey back and forth. Food and H2O should be your main priorities. Creating a grow bed inside your Cyclops is best for a sustainable food source.
You can grow Marblemelons, Lantern Fruits, and Chinese Potatoes—all good food items to farm. Alternatively, you can bring cured fish if you plan to stay out longer than necessary, as these food items do not expire. For H2O, Filtered Water is your best option. If you have a Water Filtration Machine inside your base, stocking up for H2O will be easy.
Related: How to Get Water in Subnautica?
For precautionary measures, you should also bring spare Batteries and Power Cells. You should wear the complete Reinforced Dive Suit set for deep-sea diving. A Stasis Rifle and a Repair Tool will also be necessary for your survival, especially against the Ghost Leviathan that lurks deep within the Lost River.
Finding the Lost River Entrances in Subnautica
1. Northern Blood Kelp Zone entrance
The northern Blood Kelp Zone is one of the easiest entrances to the Lost River. This entrance is quite safe to reach as there are almost no predators near this location and any Leviathans.
First, head to Lifepod 13, near a big tree in the Mushroom Forest biome. Once you get there, head northeast until you reach a steep trench where the Mushroom Forest meets the Blood Kelp Zone. Go down into the trench and follow its path until you reach a cave-like opening marked by green brine on the seabed. This indicates that you are already at the entrance to the Lost River.
2. Southern Blood Kelp Zone entrance
Another entrance to the Lost River is located in the southern Blood Kelp Zone. This path is quite dangerous as it will lead you close to the Dunes biome, home to eight Reaper Leviathans. Head to Lifepod 17 in the western Grassy Plateaus to get here. From there, follow a slight southeastern path until you end up near a large trench that leads to the Lost River entrance.
3. Sparse Reef entrance
The third entrance is located in a biome called the Sparse Reef, which is close to the Deep Grand Reef biome. Head to the Degasi base in the Deep Grand Reef to get here. When you get to the Degasi base, face northwest and follow a straight path until you see trailing pools of green brine. Follow the trail until you reach the entrance.
4. Bulb Zone entrance
The final entrance is near the Bulb Zone, quite close to the mountain biome. Extreme caution should be taken when using this path to the Lost River entrance, as you will most likely encounter at least one Reaper Leviathan on your way here. All you have to do is head to Lifepod 12 and follow a northern path once you reach the Lifepod. There will be a precipice at the end of this path. The entrance to the Lost River is directly below the precipice.
