Voyage Core - Sailing, Wind, Cargo & Storms for RPG Maker MZ

RPG Maker gives you a boat, a ship and an airship. They are teleports with a sprite. You board, you steer, you arrive, and nothing about the passage mattered. Every travel plugin on the market makes that faster. None of them makes it a journey.

Voyage Core is the journey.

The wind decides your speed, and it is not the obvious way round

Your speed depends on the angle between your heading and the wind. Straight downwind is not fastest — across the wind is. Straight upwind is impossible, and she tacks instead, giving up distance to gain speed.

That one rule turns a line on a map into a decision. A dogleg that opens her up to a reach can genuinely beat sailing straight at the mark, and four extra leagues can come back as a whole watch saved. Nothing is scripted — the wind field decides it, and the forecast on the plotting screen runs the real model so the number you plot against is the number you get.

What else is aboard

• Cargo has weight. A full hold is about 40% slower than an empty one, so capacity is a real decision instead of an inventory cap with extra steps.
• Perishable lots rot. Every lot has a keeping time and ages a watch at a time. A fast passage is worth money — which is what makes the wind matter.
• Storms are the wind you were already sailing. Weather is named from the same wind strength that drives the ship, not rolled separately. Past about 32 knots she is under storm canvas and slowing down as well as taking damage, which makes shelter a decision rather than a penalty.
• Ports remember. Land two hundred tons of grain and that port has two hundred tons of grain now — its price says so, and the glut fades over time. Trade routes wear out.
• Provisions and morale. Crew eat every watch. Run out and it shows.

It does not look like RPG Maker

The chart is drawn, not skinned: aged vellum, sounding hatchure, inked coastlines, a thirty-two line rhumb net, a compass rose with a live wind arrow, and a course that inks itself in behind her as she sails it. Heavy weather drives rain across the whole chart through a shader.

The cargo manifest is a separate screen — a ruled ship's ledger with wax seals that are sound green while a lot keeps and cracked red once it is going over, keeping-time bars, and a weight beam that tips as you load her.

There is no windowskin, no default font and no Window_Selectable anywhere in either scene. That is a measured claim, not a description: the engine gate walks the live display list and counts zero Window_Base instances on screen.

The same seas, every time

The simulation steps in watches. Conditions are drawn once per watch and held, so the same seed and the same course always produce the same passage — on every machine, and in every save file. Save in the middle of a storm, reload, and you get the same storm back.

The chart animates smoothly between watch boundaries. It is interpolating a simulation that has already been decided; it never rolls dice per frame.

What ships

• Three plugin files — the simulation, the chart scene, the manifest scene. The two scenes are optional; the simulation is not.
• 7 plugin commands and 22 parameters, including a visual struct editor for your ports.
• Raw, readable, fully commented JavaScript. Nothing is minified. Edit it freely.
• 107/107 tests green, including in-engine verification in the real MZ runtime.
• A full Readme with the workflow, the tuning table and the failure modes.

It plays well with what you already have

Voyage Core touches four core methods, all by prototype extension with the original saved and called — it never replaces one outright. Keep your vehicle plugin, your world map and your shop plugin; Voyage Core adds the passage between the ports.

The voyage record is stored as a plain versioned object on $gameSystem with a migration path, so removing this plugin later leaves a save that still loads.

Requirements

RPG Maker MZ. No new database entries, no notetags, no map changes. Add two ports and you have a sea.

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The rest of the shelf

Every one of these is a system rather than a utility, and they are built to sit beside each other:

• Bazaar Core — the economy underneath your shops: supply, demand, depleting stock and trade routes. The natural pair with this one — Bazaar Core already ships trade routes, and Voyage Core is the thing that sails them.
• Loop Core — the world resets, the player does not. Anchors, rewinds and carried knowledge.
• Chronicle Core — the consequence engine under your quest log.
• Verdict Core — evidence, contradictions and a case you can actually solve.
• Sigil Core — drawn spellcasting.
• Aperture Core — an in-game camera and a developing album.
• Chimera Core — genetics, breeding and box storage for creature collection.
• Chimera Field — which species, how rare, what variant.
• Chimera Battle — the type chart and matchup layer.

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Built by CSAF — Corey & Stephanie's Asset Factory. This plugin's code and store artwork were produced with AI assistance. It ships no audio and no in-game narrative text.