Meridian Nav

Meridian

Only for iPhone

$0.99 · Designed for iPhone. Not verified for macOS.

iPhone

Meridian is a celestial navigation toolkit built at sea by a working deck officer — fully offline, because mid-ocean is exactly where you need it. SIGHT REDUCTION Compute Hc, Zn and intercept for the Sun, Moon, four planets and 63 navigational stars. Enter your DR position, date/time and sextant altitude — get your line of position. COMPASS ERROR Check gyro error by azimuth of any celestial body — the daily routine, without the almanac and tables. Magnetic variation (WMM2025) is built in for magnetic compass work. STAR FINDER A polar sky-dome view shows exactly which bodies are observable right now from your position — plan your twilight sights before stepping out on the bridge wing. Includes an azimuth-scatter view for picking the best LOP geometry. SUN / MOON Rise, set, meridian passage and twilight times for any position and date. MARINE CHART — FULLY OFFLINE A custom offline vector chart with world time-zone (ZD) boundaries, DST awareness, ports and waypoint routes. Import route files (.rtz / .rou) straight from your ECDIS. CLOCK PLAN Generate the entire voyage's retard/advance schedule from your route — including DST transitions and solar-zone departures. Reorder or edit the changes, then export a clean calendar-style PDF or Excel notice, ready to post on board. UNIT CONVERTER The conversions a navigator actually uses, in two taps. ACCURACY & VALIDATION Every body — Sun, Moon, planets and 63 navigational stars — is cross-checked against JPL ephemeris data (the same source behind the official Nautical Almanac) to arc-minute agreement. Star positions are computed for the current date from the ESA Hipparcos catalogue. Sun azimuth verified at sea against a ship's bridge calculator, and against NOAA's solar calculator (0.000° difference). MADE FOR Deck officers who want a fast backup and sanity check, cadets and officers studying celestial navigation, and anyone who believes a navigator should still be able to find a ship without a satellite. No account. No ads. No subscription. No internet required. One-time purchase. IMPORTANT Meridian is a reference and training aid for celestial navigation. It is not a certified navigation system and does not replace official nautical publications, charts, or type-approved equipment.

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• Amplitude compass check — verify gyro/compass error against the rising or setting Sun. Event time and declination are computed automatically. • New Latitude panel (Noon / Polaris) — latitude by the noon Sun with a live meridian-passage predictor, or by Polaris at twilight. No tables needed. • Celestial fix plot — reduced sights now draw on a plotting sheet: lines of position, the least-squares fix and its scatter, at a glance. • Moon phase — the Sun / Moon screen now shows an illustrated phase disc with the illuminated fraction and the Moon's age. • Higher-resolution offline chart — coastlines sharpen automatically as you zoom in. • Clock Plan improvements — zone-change scheduling is now DST-aware and aligns each change to the ship's actual local zone. • Built-in glossary — every calculator's help now explains the terms and abbreviations it uses (Zn, Ho, intercept, amplitude, and more). • Celestial engine validated against JPL ephemeris data — Sun, Moon, planets and 63 navigation stars agree to arc-minute accuracy.

Version 1.3.0

The developer, SEUNGHYEOK CHOI, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

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    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    SEUNGHYEOK CHOI
    Size
    38.2 MB
    Category
    Navigation
    Compatibility
    Requires iOS 13.0 or later.
    • iPhone
      Requires iOS 13.0 or later.
    • iPod touch
      Requires iOS 13.0 or later.
    • Mac
      Requires macOS 11.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English
    Age Rating
    4+
    Copyright
    © 2026 Hyeok. Developed by Hyeok. All rights reserved.
  • Privacy Policy

    • Supports

    • Family Sharing

      Up to six family members can use this app with Family Sharing enabled.

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