ModsJava
Poseidon - Underwater Survival
I don't know my version or loader
Open the Minecraft launcher and look at the profile you play on — it names both, like fabric-loader-1.21.4. The version also shows in the bottom-right corner of the game's main menu.
No loader in the profile name? Then it's plain Minecraft, and these mods won't run — you need Fabric or NeoForge installed first.
🌊 Poseidon — Survival Beneath the Waves
You awaken in a shipwreck at the bottom of the ocean. Air is running out. The surface is far above. Welcome to Poseidon.
Poseidon is an underwater survival game mode where your entire island experience takes place beneath the waves. Build underwater bases, manage your oxygen, farm aquatic resources, and create a thriving kingdom on the ocean floor.
🎮 How It Works
- 🚢 Shipwrecked start — you begin in a sunken ship with basic supplies
- 🫧 Manage oxygen — air is a resource, not a given - think like a shark
- 🐠 Aquatic world — coral, kelp, fish, drowned, guardians, and ocean monuments
- 🏗️ Build underwater — create airlocked rooms, glass domes, and aquatic farms
- 👥 Multiplayer teams — build your underwater civilization together
⚙️ Features
- Unique survival challenge — water adds a layer of complexity that no other game mode has
- Custom ocean generation — configurable depth, biomes, caves, and structures
- Full team system — protection, roles, and permissions
- All BentoBox addons — challenges, levels, warps, and more
- Free and open source
📦 Installation
Requires BentoBox on a Paper server.
- Install BentoBox
- Place
Poseidon.jarintoplugins/BentoBox/addons/ - Restart
/poto start playing
📖 Docs: docs.bentobox.world | 💬 Discord: discord.gg/BentoBoxWorld | 🐛 Issues: GitHub
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.21.5, 1.21.6
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
Verified by MCModsHub
- Ships as Poseidon-1.1.0.jar — drop this file into the mods folder
- Download size: 130 KB
- Download link checked 6 Sept 2026 — working
These come from our own check of the pack file, not from the source page.