Hydro Upgrade
by Mhz
Hydro Upgrade changes how the player moves in water, adding a buoyancy system tied to air and a surface limit so swimming feels more grounded.
What it does
Swimming follows a simple buoyancy model in this mod: the player's height above the water surface is limited, and the amount of air the player has affects how the buoyancy behaves. Shallow water close to land is restricted as well, so swimming stays tied to open water. Ascending and descending speeds are capped, which replaces the default swimming movement with a more realistic version.
Water pressure is part of the system, and the player can move around above the water with the new rules applied. The mod needs Fabric and runs on Fabric only, with a file for each of 1.20.1 and 1.21.1. Its latest file targets 1.21.1 and was published on 2025-12-02 on the beta channel. The code is released under the MIT License, but the project is not open source.
Key features
Buoyancy system
A buoyancy model governs how the player floats, and it changes with the amount of air the player has.
Surface height limit
The player's height above the water surface is capped, so swimming does not carry the character far out of the water.
Shallow water restriction
Water that is too shallow near land is restricted, which keeps swimming in deeper areas.
Capped vertical speed
Ascending and descending speeds while swimming are limited, replacing the default movement.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Realistic underwater travel
Players who want swimming to behave closer to physical water can use the buoyancy and speed limits instead of the default rules.
Ocean exploration
Open-water areas suit the rules well, because the restrictions around shallow water keep the player out of the shallows near land.
Who it’s for: Players who want a more deliberate swimming experience in survival or exploration, and server owners who want water movement to follow fixed rules.
How it compares
AquaBetterfy is a Fabric mod for 1.20.1 – 1.21.1 that is client-side only, so only the player needs it, and it is released under the MIT License without being open source. Keep Swimming is a Fabric mod for 1.21.11 – 26.2 that runs on client and server, and it is open source under the Apache License 2.0. Hydro Upgrade is client and server, so both the server and every player need it, and its versions cover 1.20.1 – 1.21.1.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Hydro Upgrade | Fabric | 1.20.1 – 1.21.1 | Client and server | 2025-12-02 |
| AquaBetterfy | Fabric | 1.20.1 – 1.21.1 | Client-side only | 2026-07-13 |
| Keep Swimming | Fabric | 1.21.11 – 26.2 | Client and server | 2026-07-09 |
Questions
Does Hydro Upgrade need Fabric API?
Does the server need Hydro Upgrade?
Which game versions does Hydro Upgrade support?
In the catalog
Hydro Upgrade is one of 19,031 Adventure mods on ModsFinder, and one of 10,052 Adventure mods for Fabric. 32,366 mods support Minecraft 1.21.1.
Similar mods
What the author says
This mod aim to change minecraft default swimming mechanic to more realistic one. Hydro Upgrade add new buoyancy system that adjust with player's air and change the way player can move around above water.
Official listing
- Modrinth page
- modrinth.com/mod/hydro-upgrade
- Owner
- Mhz
- Published
- 2025-03-06
- Updated on Modrinth
- 2025-12-02
- Facts verified
- 2026-10-15