# Celestial Navigation — Sextant Sight Reduction

> Sextant sight reduction and celestial navigation calculations with map plotting. (iPhone/iPad app by Dr. Harald Merkel.)

- Source: https://appshunter.io/ios/app/celestial-navigation/id1458513224 (this page in markdown: same URL + `.md`)
- Developer: [Dr. Harald Merkel](https://appshunter.io/developer/404381431)
- Category: Navigation, Sports
- Price: $1.99
- Rating: 4.20/5 from 15 App Store ratings · 22 written reviews indexed
- Age rating: 4+
- Requires: iOS 11.0 · 51 MB
- Languages: American English, German (Germany)
- Released: 2019-04-03
- Data updated: 2026-09-07
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/celestial-navigation/id1458513224/reviews.md

## What is Celestial Navigation?

This app does all the calculations to reduce a sextant reading to a line of position on the map. All intermediate numbers are shown to check your manual calculations.

• Perpetual nautical almanac
• Calculation of the line of position (azimuth and distance)
• Draws the line of position on the map.
• Star Finder: just point your device to the sky to identify the navigational stars.
• Save your readings, choose what to show on the map.

A sextant is required to make full use of this app.

## Key features

- Sextant sight reduction calculations
- Perpetual nautical almanac
- Line of position calculation and plotting
- Star Finder for celestial identification
- Save and manage sextant readings
- Display intermediate calculation numbers

## Chart rankings

- #103 in Top Paid · Navigation (US App Store)

## Recent user reviews (10 of 22)

All indexed reviews: https://appshunter.io/ios/app/celestial-navigation/id1458513224/reviews.md

### 1/5 — Starfinder stopped working

*2026-07-17, version 1.4*

Just looked it up today again and star finder is not showing any information.

### 5/5 — Great tool!

*2026-02-27, version 1.4*

I use this for sextant practice, plugging in my readings and comparing them to my known location to improve my sighting technique. Quick, easy, and accurate. It hasn’t been updated in 5 years, which is troubling, but it is still working on iOS 26.3.

### 5/5 — Position calculation

*2025-06-26, version 1.4*

This app is really good. Everything you need, full service. Not hard to learn. 

Wish list: option for latitude longitude and time in decimal seconds. Verbose position output and confidence value.

### 3/5 — Dip error

*2024-11-22, version 1.4*

From height this calculates a positive dip.
I think that dip is always a subtraction from read on the sextant.

### 5/5 — Appli géniale

*2024-08-30, version 1.4*

Hyper intuitive et simple. Une visée plus calcul en moins d’une minute. Toutes les droites sont mémorisées. On peut sélectionner celles que l’on va retenir en final. Le transport de droites se fait automatiquement. Il suffit de rentrer le cap et la vitesse (à partir du point arbitraire). Le rendu sur carte est super. Je l’utilise depuis des mois et ai comparé la précision par rapport à d’autres applis, y compris le calcul d’estime. Tout est exact. Un vrai jeu de descendre aussi une étoile, planète, ou la lune, le tout en ayant le téléphone dans sa poche. Le starfinder aide à confirmer l’emplacement des astres en mode automatique ou à l’heure et lieu que l’on souhaite. Le plus de cette appli : la rentrée des données sur une seule page, ce qui évite les erreurs. Un seul coup d’œil permet de confirmer les paramètres rentrés et déceler un éventuel oubli.

### 5/5 — Wow

*2024-08-08, version 1.4*

This app is terrific! It is good to learn the “long way” of plotting your position but once you learn, then this app makes it so much easier and faster. All you need is your sextant and your watch and let the fun begin.

### 5/5 — Perfect.

*2024-07-07, version 1.4*

You put your sextant reading and it will give you a line of position.   No need for nautical almanacs.  But it does show all the variable values so you can double check your own calcs.

### 5/5 — Exceptionally Accurate and easy

*2024-03-13, version 1.4*

This is a terrific app for reducing celestial navigation sights. Easy to use and is exceptionally accurate. You can change the settings to suit your preferences. It will store your sights and allow you to select which ones to plot. I’ve tested it many times against hand calculations and every time and it comes right on the money. I highly recommend this app.

### 5/5 — Einfach und sehr gut

*2023-09-29, version 1.4*

Bitte jetzt noch die Farben der Linien/Kreise etc. wählbar machen,
großes Danke wenn es möglich wär.

### 4/5 — Bug with iPad when using star finder .

*2023-07-18, version 1.4*

Great app but the star finder displays stars for a second then goes blank on my iPad .

## Frequently asked questions about Celestial Navigation

### What is Celestial Navigation used for?

Celestial Navigation is used to calculate your position on Earth using observations of celestial bodies like stars and the sun. This app specifically helps reduce sextant sights to lines of position on a map.

### Does Celestial Navigation require a sextant?

Yes, a sextant is required to make full use of Celestial Navigation. The app performs calculations based on readings taken with a sextant.

### How much does Celestial Navigation cost?

Celestial Navigation is a paid app, priced at $1.99. This one-time purchase grants access to all its features without further charges.

### What devices support Celestial Navigation?

Celestial Navigation is supported on iPhone, iPad, and iPod devices. It is designed for Apple's mobile operating system.

### How often is Celestial Navigation updated?

The latest version of Celestial Navigation is 1.4, last updated on August 20, 2020. While updates may not be frequent, the core functionality remains stable for its purpose.

### What is the age rating for Celestial Navigation?

Celestial Navigation has an age rating of 4+. This indicates it is suitable for users of all ages and does not contain mature content.

### Can I see my calculations in Celestial Navigation?

Yes, Celestial Navigation shows all intermediate numbers for your sextant readings. This allows you to check your manual calculations against the app's results.

### Does Celestial Navigation have ads?

No, Celestial Navigation does not contain advertisements. As a paid application, it provides an ad-free experience for its users.

## Version history (last 5 releases)

### 1.4 — 2020-08-20

• Supports now dark modus.
• Alphabetical star list as option.
• Bug fixes, e.g. fixed missing possibility to enter negative index error on some devices.

### 1.3 — 2019-04-15

- Averaged position is now shown on map.
- Export the result as PDF file.

### 1.2 — 2019-04-08

Now with manual.

### 1.1 — 2019-04-06

Now also with German version.

### 1.0 — 2019-04-03

No release notes.

## Apps similar to Celestial Navigation

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Altimeter+](https://appshunter.io/ios/app/altimeter-plus/id417204570) | 4.5 (700) | $1.99 | Navigation |
| [MagVar](https://appshunter.io/ios/app/magvar/id1670958717) | 5.0 (1) | $0.99 | Navigation |
| [Ecliptic Compass](https://appshunter.io/ios/app/ecliptic-compass/id1584943153) | 5.0 (3) | $1.99 | Navigation |
| [My Position HD](https://appshunter.io/ios/app/my-position-hd/id377915185) | 2.0 (2) | $1.99 | Navigation |
| [Sun Seeker - Sunlight Tracker](https://appshunter.io/ios/app/sun-seeker-sunlight-tracker/id330247123) | 4.8 (12,846) | $11.99 | Navigation |
| [Cruise Nav](https://appshunter.io/ios/app/cruise-nav/id1092067489) | 1.0 (1) | $1.99 | Navigation |

## More apps by Dr. Harald Merkel

- [Trace Tuner](https://appshunter.io/ios/app/trace-tuner/id404381428)
- [Helmsman's Kit](https://appshunter.io/ios/app/helmsmans-kit/id1220932986)
- [Pure Set](https://appshunter.io/ios/app/pure-set/id1540789538)

All apps by Dr. Harald Merkel: https://appshunter.io/developer/404381431

## Related topics

[celestial navigation](https://appshunter.io/ios/topics/celestial-navigation) · [sextant navigation](https://appshunter.io/ios/topics/sextant-navigation) · [celestial navigation 360](https://appshunter.io/ios/topics/celestial-navigation-360) · [sextant](https://appshunter.io/ios/topics/sextant)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*