Sea Sick

In Minecraft you can cross a storm-tossed ocean without blinking. Not anymore.

Seasick gives your character a stomach. The sea is simulated from the wind, the weather, the open water upwind, the depth and the biome; your boat rolls, pitches and heaves like a real one; and your body reacts to that motion the way real bodies do, using the motion-sickness weighting of the ISO 2631-1 standard.

Look at the horizon. Take the helm. Eat something plain. Or lean over the side.

100% client-side: works in singleplayer and on any server, even vanilla ones. Nothing changes for other players.

🌬 A sea worth sailing

• Wind follows the weather — a shifting breeze when clear, fresh wind in the rain, a gale in thunderstorms — and slowly turns.
• Waves grow with the wind (Pierson–Moskowitz), but only over enough open water upwind: a lake stays flat, the open ocean builds up. They break over shallows, die down in rivers, swamps and under sea ice, and vanish under a roof.
• Your boat answers to where the waves come from: beam seas roll you, head seas pitch you and slam the bow, following seas make you surf. Sail into the waves at full speed and you meet them far more often (encounter frequency). Waves come in sets — every seventh wave is bigger. The hull creaks at the end of each roll.
• Sea state on the Douglas scale, wind on the Beaufort scale.

🤢 A stomach that reacts like yours

Motion sickness comes from a conflict between your inner ear and your eyes. Seasick turns the accelerations you feel into a sickness dose (most nauseating around 0.1–0.25 Hz — exactly ocean swell) while your body slowly recovers. Every situation has its own balance: play it smart and you can ride out a storm.

What helps: eyes on the horizon (−45%) · taking the helm — whoever steers anticipates the motion (−35%) · closing your eyes, hold Z (−55%) · something plain to eat: bread, cookies, dried kelp (−25%) · a honey bottle, our ginger (−40%) · an artificial horizon when the real one is gone · your sea legs (up to −60%).

What hurts: reading at sea — inventory, chests, chat, signs (+50%), a book (+90%), a map (+60%) · the spyglass (+120%) · staring at your feet (+35%) · being a passenger (+25%) · heavy, raw or spoiled food, milk · an empty stomach · darkness with no horizon · Nausea.

Five stages

😊 Fine → 😐 Uneasy (yawns, heavy eyelids) → 🤢 Queasy (pale, mouth watering, cold sweat) → 🤮 Sick (dark edges, churning stomach, trembling hands, slipping oars) → 😵 About to be sick.

The moment of truth

Two heaves warn you: lean over the side (turn sideways and look down). Over the rail it's clean and you feel much better. Otherwise… it's in the boat. It comes out the colour of your last meal (glow berries glow). Then a little relief… and if nothing changes, it starts again — dry heaves this time. (Gross effects can be turned off.)

🧂 Sea legs & land sickness

• Sea legs: time at sea slowly hardens you, from Landlubber to Deckhand, Sailor, Old Salt and Sea Dog. Long stays ashore wear it off.
• Land sickness (mal de débarquement): after a long voyage, the ground keeps swaying for a while and your walk drifts.
• Camels, the ships of the desert, rock you too.

📓 Ship's log (O)

Sea state, waves, wind and open water; how you feel and everything affecting you right now, with its exact effect; a forecast ("if nothing changes: sick in 1:20"); and your memories at sea. Careful: reading it at sea counts as reading.

⚙ Comfort & configuration

This mod moves the picture on purpose. If you get motion sick in real life, turn on reduceMotion (still camera — the sea is shown by the artificial horizon and the gauge) or lower motionScale.

config/seasick-client.toml: susceptibility, creativeImmune, seaLegs, seaLegsRate, landSickness, camels, motionScale, reduceMotion, swayAim, screenEffects, grossEffects, affectControls, artificialHorizon, hud, messages, sounds.

Client commands: /seasick status | logbook | sea <calm…phenomenal|auto> | set <0-100> | sealegs <0-100> | vomit | landsick | reset.

✦ Requirements

Client only. One jar per version (pick the matching file on the Files tab):

• Minecraft 1.21 – 1.21.1, Forge 51+ or NeoForge 21.0 / 21.1, Java 21
• Minecraft 1.20.1, Forge 47, Java 17
• Minecraft 26.3, NeoForge 26.3, Java 25 (OpenGL and Vulkan)

🇫🇷 En français

Dans Minecraft, on traverse l'océan en tempête sans sourciller. Seasick donne un estomac à votre personnage : la houle est simulée (vent, météo, eau libre au vent, fond, biome), le bateau roule, tangue et pilonne selon l'allure, et le mal de mer suit la pondération de la norme ISO 2631-1. Regardez l'horizon, tenez la barre, fermez les yeux, mangez du sec ou du miel… ou penchez-vous par-dessus bord. Cinq stades, pied marin (de Terrien à Loup de mer), mal de débarquement, dromadaires, journal de bord avec prévision, horizon artificiel et réglages de confort. Mod 100 % client, entièrement traduit en français.

Source code & issues: https://github.com/Loup0007A/seasick-mod — MIT licence.