Underwater Swim Fix (MC-220390)

Fixes the bug where if you hit an entity while swimming and holding the sprint hotkey, the server will think that you are not swimming anymore, while the client does. resulting in weird behavior.

16.9K Downloads

fabricgame-mechanicsutility

Rent Server with this Mod

About this Mod

Fixes MC-220390 a bug where if you hit an entity while swimming and holding the sprint hotkey, the hitboxes server and clientside will be different. Resulting in weird behaviour where the client thinks that theyre swimming while the server doesnt think that. So when you for example try to go into a 1x1 block space while experiencing this bug, you will glitch out until you stop swimming and swim again.

The bug really annoyed me in monuments so I fixed it.

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Available Versions

Underwater Swim Fix (MC-220390) 1.0.3release

MC 1.21.11-pre1, 1.21.11-pre2, 1.21.11-pre3, 1.21.11-pre4, 1.21.11-pre5, 1.21.11-rc1, 1.21.11-rc2, 1.21.11-rc3, 1.21.11, 26.1-snapshot-1fabric

January 6, 2026

Underwater Swim Fix (MC-220390) 1.0.2release

MC 1.18, 1.18.1, 1.18.2, 1.19, 1.19.1, 1.19.2, 1.19.3, 1.19.4, 1.20, 1.20.1, 1.20.2, 1.20.3, 1.20.4, 1.20.5, 1.20.6, 1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10fabric

January 6, 2026

Underwater Swim Fix (MC-220390) 1.0.1release

MC 1.13, 1.13.1, 1.13.2, 1.14, 1.14.1, 1.14.2, 1.14.3, 1.14.4, 1.15, 1.15.1, 1.15.2, 1.16, 1.16.1, 1.16.2, 1.16.3, 1.16.4, 1.16.5, 1.17, 1.17.1, 1.18, 1.18.1, 1.18.2, 1.19, 1.19.1, 1.19.2, 1.19.3, 1.19.4, 1.20, 1.20.1, 1.20.2, 1.20.3, 1.20.4, 1.20.5, 1.20.6, 1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10fabric

October 4, 2025

Underwater Swim Fix (MC-220390) 1.0.0release

MC 19w11b, 19w12a, 19w13a, 19w13b, 3D-Shareware-v1.34, 19w14a, 19w14b, 1.14-pre2, 1.14.2-pre2, 1.14.2-pre3, 1.14.2-pre4, 1.14.2, 1.14.3-pre1, 1.14.3-pre2, 1.14.3-pre3, 1.14.3-pre4, 1.14.3, 1.14.4-pre1, 1.14.4-pre2, 1.14.4-pre3, 1.14.4-pre4, 1.14.4-pre5, 1.14.4-pre6, 1.14.4-pre7, 1.14.4, 19w34a, 1.15, 1.15.1, 1.15.2, 1.16, 1.16.5, 1.17, 1.18.1, 22w03a, 22w05a, 22w06a, 22w07a, 1.18.2-pre1, 1.18.2-pre2, 1.18.2-pre3, 1.18.2-rc1, 1.18.2, 22w11a, 22w12a, 22w13a, 22w13oneblockatatime, 22w14a, 22w15a, 22w16a, 22w16b, 22w17a, 22w18a, 22w19a, 1.19-pre1, 1.19-pre2, 1.19-pre3, 1.19-pre4, 1.19-pre5, 1.19-rc1, 1.19-rc2, 1.19, 22w24a, 1.19.1-pre1, 1.19.1-rc1, 1.19.1-pre2, 1.19.1-pre3, 1.19.1-pre4, 1.19.1-pre5, 1.19.1-pre6, 1.19.1-rc2, 1.19.1-rc3, 1.19.1, 1.19.2-rc1, 1.19.2-rc2, 1.19.2, 22w42a, 22w43a, 22w44a, 22w45a, 22w46a, 1.19.3-pre1, 1.19.3-pre2, 1.19.3-pre3, 1.19.3-rc1, 1.19.3-rc2, 1.19.3-rc3, 1.19.3, 23w03a, 23w04a, 23w05a, 23w06a, 23w07a, 1.19.4-pre1, 1.19.4-pre2, 1.19.4-pre3, 1.19.4-pre4, 1.19.4-rc1, 1.19.4-rc2, 1.19.4-rc3, 1.19.4, 23w12a, 23w13a, 23w13a_or_b, 23w14a, 23w16a, 23w17a, 23w18a, 1.20-pre1, 1.20-pre2, 1.20-pre3, 1.20-pre4, 1.20-pre5, 1.20-pre6, 1.20-pre7, 1.20-rc1, 1.20, 1.20.1-rc1, 1.20.1, 23w31a, 23w32a, 23w33a, 23w35a, 1.20.2-pre1, 1.20.2-pre2, 1.20.2-pre3, 1.20.2-pre4, 1.20.2-rc1, 1.20.2-rc2, 1.20.2, 23w40a, 23w41a, 23w42a, 23w43a, 23w43b, 23w44a, 23w45a, 23w46a, 1.20.3-pre1, 1.20.3-pre2, 1.20.3-pre3, 1.20.3-pre4, 1.20.3-rc1, 1.20.3, 1.20.4-rc1, 1.20.4, 23w51a, 23w51b, 24w03a, 24w03b, 24w04a, 24w05a, 24w05b, 24w06a, 24w07a, 24w09a, 24w10a, 24w11a, 24w12a, 24w13a, 24w14potato, 24w14a, 1.20.5-pre1, 1.20.5-pre2, 1.20.5-pre3, 1.20.5-pre4, 1.20.5-rc1, 1.20.5-rc2, 1.20.5-rc3, 1.20.5, 1.20.6-rc1, 1.20.6, 24w18a, 24w19a, 24w19b, 24w20a, 24w21a, 24w21b, 1.21-pre1, 1.21-pre2, 1.21-pre3, 1.21-pre4, 1.21-rc1, 1.21, 1.21.1-rc1, 1.21.1, 24w33a, 24w34a, 24w35a, 24w36a, 24w37a, 24w38a, 24w39a, 24w40a, 1.21.2-pre1, 1.21.2-pre2, 1.21.2-pre3, 1.21.2-pre4, 1.21.2-pre5, 1.21.2-rc1, 1.21.2-rc2, 1.21.2, 1.21.3, 24w44a, 24w45a, 24w46a, 1.21.4-pre1, 1.21.4-pre2, 1.21.4-pre3, 1.21.4-rc1, 1.21.4-rc2, 1.21.4-rc3, 1.21.4, 25w02a, 25w03a, 25w04a, 25w05a, 25w06a, 25w07a, 25w08a, 25w09a, 25w09b, 25w10a, 1.21.5-pre1, 1.21.5-pre2, 1.21.5-pre3, 1.21.5-rc1, 1.21.5-rc2, 1.21.5, 25w14craftmine, 25w15a, 25w16a, 25w17a, 25w18a, 25w19a, 25w20a, 25w21a, 1.21.6-pre1, 1.21.6-pre2, 1.21.6-pre3, 1.21.6-pre4, 1.21.6-rc1, 1.21.6, 1.21.7-rc1, 1.21.7-rc2, 1.21.7, 1.21.8-rc1, 1.21.8, 25w31a, 25w32a, 25w33a, 25w34a, 25w34b, 25w35a, 25w36a, 25w36b, 25w37a, 1.21.9-pre1, 1.21.9-pre2, 1.21.9-pre3, 1.21.9-pre4, 1.21.9-rc1fabric

April 25, 2025

How to Install Underwater Swim Fix (MC-220390) on Your Server

Order Server

Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).

Set fabric Loader

In the panel under "Egg", select the fabric loader and matching Minecraft version (26.1-snapshot-1).

Install Mod

Open the mod browser in the dashboard and search for "Underwater Swim Fix (MC-220390)". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.

Compatibility

Mod Loaders

fabric

Minecraft Versions

26.1-snapshot-1, 1.21.11, 1.21.11-rc3 (+281 more)

Server-side

✓ Required

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Underwater Swim Fix (MC-220390) server crashes on startup – what to do?

Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (26.1-snapshot-1). You can switch loaders with one click in the panel.

Is Underwater Swim Fix (MC-220390) compatible with fabric?

Underwater Swim Fix (MC-220390) officially supports fabric for Minecraft 26.1-snapshot-1, 1.21.11, 1.21.11-rc3. The Mado dashboard automatically detects incompatible loader combinations.

Server lagging with Underwater Swim Fix (MC-220390) – how to optimize performance?

Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Underwater Swim Fix (MC-220390) consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.