Fabric Mods for Minecraft 1.21
Browse 31 free Fabric mods for Minecraft 1.21 — popular picks include Sea Weapons, Liquid Fog Begone, Ocean's Delight (Polymer Port).
Updated daily
Sea Weapons
A mod that adds new sea themed weapons to minecraft!
Liquid Fog Begone
A simple mod that allows you to control how dense the fog is while underwater or in lava.
Ocean's Delight (Polymer Port)
Polymer Port of Ocean's Delight

Pickles to Skellys
Client-side Fabric mod for Donut SMP that disguises sea pickles as skeleton spawners and iron chestplates as elytras.
Impenduits
Adds weak forcefields powered by Hearts of the Sea
Boatism
Add new and fully customizable Boat Engines to Minecraft. Traveling by sea will never be the same again!

Maddy's Origins
A comprehensive rework of Origins, replacing the stock origins with 9* new, varied origins. Become a featherweight Avian, a semi-aquatic Amphibian, a durable Construct, a nimble Critter, and more!
Cyra
A Minecraft mod that reveals the secrets of the ocean!
Hold Your Breath
When you go underwater in-game, you need to hold your breath in real life.
Better Turtle Helmets
Reworks the turtle helmet to provide continous water breathing underwater at the cost of losing durablility overtime.
Redstone Underwater
Redstone can now be waterlogged!
Exodus 14:27
Fixes MC-278019 bug to restore sea level in superflat worlds.

Simple Mermaid Tails
This Mod adds Mermaid Tails, thats it. This is kinda a fork from my Mako Mermaids Mod but without the Powers etc.
ClimateCraft
Adds climate change mechanics. Building, mining, and smelting emit CO2, plants absorb it. Keep the environment in balance or suffer sea level rise, droughts, and wildfires!
Monster Origins
(WIP) Minecraft 1.20.1 (and now 1.21.1) / Fabric addon for Origins that adds four origins Arachne (a humanoid spider), Medusa (a gorgon), Harpy (a storm-wind bird-woman), and Mermaid (a singer of the deep) each built around a different playstyle
Water Enhanced
Expands ocean gameplay with new resources, gear, and aquatic mechanics while staying true to vanilla.
Drown Panic
"An immersive mod that enhances survival atmosphere underwater with a wide screen vignette (tunnel vision) and realistic heartbeat sounds when drowning."
Breathe Underwater
A simple mod to let you breath under water without any potion effect Theres many dangers already, dont let the sea be other
Stay Flooded!
A mod that prevents air pockets from forming when submerged blocks are destroyed, perfect for an aquatic playthrough :-)
DrownForReal
Drown For Real adds realistic player panic animations when your underwater oxygen bar hits zero. Built for Fabric, it features custom flailing animations that smoothly blend in and out over a fraction of a second using player-animation-lib.
No Boats
This mod removes all boats from Minecraft, forcing you to travel across water the slow way. It makes oceans feel bigger and exploration harder since you can’t just zip across huge distances anymore.
Toads Simple Origins: Fish Bowl
Adds a custom piece of armor that allows custom origins datapacks to add a way to spend more time on land or in the nether without completely removing the challenge of only breathing underwater.
Underwater Torch
Place all torches underwater and they will still emit light Full Fabric 1.20.1 + 1.21.1 + 1.21.4
Aqua Verse
AquaVerse expands aquatic biodiversity of minecraft
Special Potions
Adds new powerful potions with unique abilities like Fire, Ocean, Wind, Warden, Ender, Speed, and Strength effects for survival and PvP gameplay.
vegan-fishing
A Fabric mod for Minecraft Java 1.21.11 that replaces the fish loot table with plant-based and ocean-themed alternatives, allowing players to enjoy the relaxing fishing minigame without harming any virtual wildlife.
Splinecart Aquatic
This is a small mixin designed to be used with the Splinecart mod. It makes Splinecart track ties able to be placed in water, that way you can make under water roller coasters or waterslides.
Chewing Gum
This mod adds a pack of gums with 3 pieces inside used to remove nausea
Lili's Lucky Lure Mod (1.21.1, 1.20.1) – Catch More than Fish
Lili's Lucky Lure Mod expands the fishing mechanics in Minecraft by adding new ways to fish, decorative fishing blocks, and unique fish traps. You can find fish & rubble pools in rivers and oceans, use new tools like a bamboo rod, spear, or even dynamite, and decorate with frames and nets. Features: Fish & rubble […]
Re:squake Mod (1.21.4, 1.20.1) – Implements Quake-style Movement Mechanics
Re:squake Mod is a Kotlin rewrite of the classic mod that introduces quake-style movement mechanics to Minecraft. It enhances gameplay with advanced movement techniques and customizable settings. Features: Implements quake-style movement mechanics. Includes advanced movement techniques: bunnyhopping, trimping, and sharking. Features a basic speed indicator for better movement tracking. Offers in-game configuration with adjustable values. […]
MegaGanDon
MegaGanDon is a giant aquatic mob (megalodon) for Fabric 1.21.x: realistic swimming, neutral behavior with aggro when attacked, jumping on land, spawning eggs, sponge drops, and localization. Lightweight and customizable.