SN2PropulsionTweaks

SN2PropulsionTweaks

Get around faster in Subnautica 2 — a deliberately conservative UE4SS Lua mod that boosts your swim speed and the Tadpole's speed, configured in-game via SN2ModSettings. Built with clipping safety in mind: speeds are capped where the game (and physics) stay happy.

What it does

Faster Swimming - Swim at the game's natural max-swim speed (~2×) without needing fins equipped. Fins and the Wakemaker still stack on top. Off = vanilla.

Faster Tadpole - Increases the Tadpole's acceleration → higher cruising speed (2×). Off = vanilla. |

Simple ON/OFF — flip a toggle off and the vanilla value is restored.

Why just on/off (no slider)?

The effect is binary. Subnautica 2 soft-caps swim speed at roughly 2× base (the ceiling you'd hit with Improved Fins + Wakemaker) — push past it and the game just clamps you, and higher speeds start clipping through terrain and outrunning world streaming. So there's nothing meaningful between "vanilla" and "the ceiling" — a toggle says exactly that. The Tadpole is held to 2× for the same safety reason: fast vehicles punch through geometry far more easily than a swimming player.

Single-player / host only

Movement is server-authoritative, so this works in single-player and for the host of a co-op session. Joining players won't see the effect on their own movement.

Requirements

1. UE4SS for Subnautica 2 — (https://www.nexusmods.com/subnautica2/mods/36) / (https://github.com/Subnautica2Modding/Subnautica2-UE4SS)

2. SN2ModSettings — (https://www.nexusmods.com/subnautica2/mods/20) — the in-game slider UI.

Installation

1. Make sure UE4SS is installed (`dwmapi.dll` next to `Subnautica2-Win64-Shipping.exe`, `ue4ss/` folder beside it).

2. Extract this archive so the `SN2PropulsionTweaks/` folder lands in:

<game>\Subnautica2\Binaries\Win64\ue4ss\Mods\

3. Add this line to `ue4ss\Mods\mods.txt`:

SN2PropulsionTweaks : 1

(loads it before SN2ModSettings so it appears in the settings UI; otherwise just restart once).

4. Launch → Settings → Mods → Propulsion Tweaks.

How it works (technical)

Swim speed - `UWEMovementSetComponent:SetBaseSwimSpeed()` - Proper setter UFunction, applied only to the local player pawn's component (matched by owner, so creatures aren't sped up). ×2 when on, ×1 (vanilla) when off. |

Tadpole speed - `UWESubmersibleMovementComponent. MaxSwimAcceleration` - Direct write. Higher acceleration → higher thrust-vs-drag top speed. ×2 when on, ×1 when off. |

Vanilla base values are snapshotted once so toggling off cleanly restores the original. Deliberately not touched: creatures, swimming friction, turn rate, water currents.

Credits

- UE4SS — ported for Subnautica 2 by the (https://github.com/Subnautica2Modding/Subnautica2-UE4SS) group.

- SN2ModSettings by (https://github.com/Just-Chaldea/SN2-ModSettings) — the in-game slider UI.

- ConfigManager pattern adapted from Capacity & QuickBar Tweaks by (https://www.nexusmods.com/subnautica2/mods/252).

License

MIT — see (./LICENSE).

Changelog

- Simplified to ON/OFF toggles. The effect is binary (the game soft-caps swim speed at ~2×), so the 1–2× sliders were redundant with the enable toggles.

- Toggling off now cleanly restores the vanilla value.

- Initial release: player swim speed and Tadpole speed via SN2ModSettings sliders. Conservative caps for clipping safety.