ZENZI ARCADE
How the Celestial Navigation Simulation Works
Lunars brings the mathematical art of 18th-century nautical navigation to life. As captain of a sailing vessel crossing vast ocean expanses, you do not have satellite coordinates or digital maps. Instead, your crew relies on dead reckoning—plotting hourly compass headings and estimated knots on paper charts. With every hour that passes, unseen ocean currents, crosswinds, and helm drift push your vessel off course, causing your plotted position to drift progressively further from reality.
To uncover your true location, you must practice celestial navigation. Whenever the night sky clears, you can bring up your brass sextant to take sight measurements of prominent stars and the Moon. Each successful sight yields a Line of Position (LOP) on your navigational chart. A single sight proves your ship lies somewhere along that bearing; a second sight taken on a different celestial body creates an intersecting cross. Where these two lines cross is your true celestial fix, dispelling dead reckoning errors and keeping your voyage on track toward landfall.
Sextant & Dead Reckoning Controls
Navigate your vessel across open water using intuitive keyboard hotkeys or on-screen console buttons:
- A or ArrowLeft (or Left Button): Steers your vessel course 6 degrees counter-clockwise to adjust heading.
- D or ArrowRight (or Right Button): Steers your vessel course 6 degrees clockwise to align toward destination coordinates.
- S (or Sight Button): Takes a sextant sight on the currently visible celestial star or lunar body, drawing a Line of Position.
- Spacebar: Advances ship time by one hour, sailing along your current course, shifting cloud cover, and advancing planetary bodies.
- R: Restarts the current passage leg, clearing chart marks and returning ship position to the departure port.
| Command | Input Key / Touch | Navigational Consequence |
|---|---|---|
| Steer Port / Starboard | A / D or ← / → | Adjusts magnetic compass course by 6-degree increments. |
| Shoot Sextant Sight | S / Sight Button | Plots an astronomical Line of Position (LOP) on chart. |
| Advance One Hour | Space / Advance Button | Sails one hour forward; advances sky dome and cloud cover. |
| Reset Crossing | R | Resets current ocean leg back to starting coordinates. |
How to Navigate Leg 4 (The Vega Cloud Trap)
Leg 4 tasks you with navigating through a stormy northern corridor toward the Azores. Beginner navigators often run into disaster here by waiting to shoot sights until they suspect they are lost. Because heavy overcast skies roll in between midnight and 3 AM, waiting leaves your sextant useless for several consecutive hours while strong cross-currents push your hull toward shallow shoals.
The winning tactic is taking proactive twilight sights. Shoot Polaris immediately as dusk settles to pin your vessel's latitude coordinate. Next, rotate your course slightly toward Vega while the eastern horizon remains cloud-free. Taking that second sight early in the shift creates an exact crossing fix before dense fog rolls in. Once your fix is secured, you can safely advance through cloudy night hours with confidence in your heading.
Strategies for Tougher Ocean Passages
Later voyages introduce shifting trade winds, persistent marine overcast, and narrow island archipelagos:
- The Madeira Run: Trade winds push hard to the south. Compensate in advance by steering 12 degrees higher into the wind than your straight-line destination bearing.
- The Equatorial Doldrums: Ship speed drops during daylight calm. Do not waste sights on faint midday stars; conserve time and take sights during crisp dawn and dusk horizons.
- The Channel Approaches: Landfall is bordered by hazardous granite reefs. Never sail through unverified dead reckoning plots for more than two consecutive hours without shooting a confirmatory star fix.
Sextant Sights & Navigation FAQ
Why does my true position differ from the dotted dead reckoning line?
Dead reckoning only calculates where your ship should be based on compass heading and theoretical speed. Ocean swells and leeway drift constantly nudge your ship off course. Only celestial fixes reveal your authentic geographical coordinates.
Can I take a celestial sight when clouds cover the sky?
No, heavy cloud cover blocks celestial bodies from the sextant mirror. If overcast obscures the sky, you must navigate on dead reckoning until skies clear, or advance hours until a break in the weather reveals a clear horizon.
How many sights do I need to confirm an exact location?
A single sight provides one Line of Position, confirming you are on that line but leaving your exact spot uncertain. You need two intersecting sights from different celestial bodies to generate an indisputable position fix.
Built with pure vanilla HTML5 canvas and standard Web Audio (no external engines or heavy libraries).