Abyssia

Dive past the bedrock. The real deep sea is waiting.

Abyssia adds a whole new layer of ocean beneath the world: a vast, dark, pressurised abyss populated by more than 50 real deep-sea species. Find a fissure in the ocean floor, follow it down, and keep going. There are no portals and no loading screens, just the long swim into the dark.

🌊 The Deep Layer

• A continuous deep-ocean layer generated below the vanilla bedrock band (Y -64 to -368).
• Reach it through deep fissures that split the ocean floor. You descend the whole way yourself, with no teleport.
• The default world type keeps vanilla terrain on the surface. Choose the optional Abyssia Ocean world type for an all-ocean world.
• 17 deep-sea biomes, including Twilight Reef, Abyssal Forest, Deep Crystal Fields, Volcanic Deep, Thermal Vents, Brine Lakes, Glow Gardens, Frost Abyss, Sunken Ruins, Bone Graveyard, Abyssal Trench and the Hadal Zone.
• Biomes form large, readable regions instead of tiny patches, so every expedition feels like a journey.
• Huge caverns, gas pockets, rifts and a full family of deep stones, ores and building blocks.
• Seabed structures that fit each biome: rock formations, vent chimneys, ruins and more.

🐟 Real Deep-Sea Life

Every creature is based on a real species and lives at depths that match its real range.

• Anglerfish, Gulper Eel, Barreleye, Fangtooth, Viperfish, Black Dragonfish, Blobfish, Tripod Fish
• Goblin Shark, Frilled Shark, Pacific Sleeper Shark, Cookiecutter Shark, Bluntnose Sixgill Shark
• Giant Squid, Vampire Squid, Firefly Squid, Bigfin Squid, Dumbo Octopus
• Giant Isopod, Japanese Spider Crab, Supergiant Amphipod, Sea Pig, Giant Sea Spider
• Hydrothermal vent communities: Tubeworms, Yunohana Crabs, Squat Lobsters, Scaly-foot Snails, Vent Eelpouts and more cluster around the vents.
• Drifting jellies such as the Atolla Jelly, Helmet Jelly, Giant Phantom Jelly and Deepstaria pulse and glide with the currents.
• …and many more, including the Mariana Snailfish, Oarfish, Sea Lily and Venus' Flower Basket.

Creatures have their own behaviours. They flee and hunt, they move between depths, and their bioluminescence glows in the darkness. Some of them can be harvested for food or crafting materials.

Already using other ocean mods? Abyssia can detect their sea creatures automatically and let them spawn at suitable depths (configurable).

🌀 A Living Ocean

• Ocean currents push players, mobs, items and boats.
• Natural current streams cross the sea floor and are visible as streaks of particles.
• Marine snow, depth fog and lighting that change as you go deeper.
• A custom deep-sea title screen panorama.

🌿 Resources & Crafting

• Deep-sea resource plants that ripen and regrow, giving fibres, shells and other materials.
• New ores and minerals, each with its own raw, crystal and powder forms.
• Fish, eel and shark meat can be eaten and cooked. Jelly tentacles are useful crafting materials.

🤿 Diving Gear

• An entry diving set made with vanilla materials, which refills your air as you explore the shallows.
• Advanced deep-sea gear for the crushing depths below.

⚡ Industry Powered by the Abyss

• Thermal-vent generators turn the heat of hydrothermal vents into Forge Energy (FE).
• Machines such as crushers, smelters and alloy furnaces, plus batteries and an energy cable network.
• Compatible with other FE mods: Abyssia cables can deliver power to their machines.
• Electric drills and cutters, plus a propulsion screw that pulls you through the water.

🏠 Underwater Bases

• Habitat modules: dry, air-filled rooms that you place on the sea floor. Their hatches connect to each other automatically.
• Base equipment: lockers, a wall workbench that also charges tools, a 3D constructor and a scan room.
• Waypoint beacons that mark places on your HUD so you can always find your way home.

📋 Requirements & Compatibility

• Minecraft 1.20.1, Forge 47.x
• New worlds only. The deep layer changes world height, so Abyssia cannot be added to an existing world.
• Works with Embeddium and Oculus/Iris shader packs.
• JEI is optional and adds information pages for materials.
• Most features can be adjusted in the config files, including spawn rates, currents and visual effects.

🐞 Feedback

Found a bug or have an idea? Please open an issue. Screenshots and the seed are always helpful.