iMariner Celestial Navigation is a complete toolbox : sight, fix, meridian, starfinder, solar compass
Also embedded : nautical almanac (sun, moon, planets, starts) and astronomical computation (no more need for HO-249/HO-229 tables)

v2.3 : Update the value of DeltaT (67.4s) for 2013 from

- displays almanac informations : Sun, Moon, Venus, Mars, Jupiter, Saturn and 92 brightest stars. At this step, you can use these almanac data with HO.249 tables, if you want to reduce manually.

- reduces a sight : getting your observed altitude and the precise time, it calculate Intercept and Azimut. You don't need any calculation ! Simply report Intercept and Azimut to your navigational chart.

- You can save your observations by passages and send them by email in CSV format

- take a fix : with two sights, iMariner is able to calculate your position (latitude/longitude)

- meridian passage : iMariner helps you to take observations mandatory to know your position (latitude/longitude)

- sight preparation : iMariner proposes you the best objects, here position (azimut and elevation), and the approximate time of the day the observation can take (nautical_twilight or nautical dawn).

iMariner is a standalone application. It doesn't require internet connection. It is light and calculations are optimized to save energy on your boat.

Includes a solar compass (and moon compass too).


iMariner has been inspirated by astronomical works of the following people.

Brightest Stars Catalog

Extraction of 92 stars >= 2.5 Mag from the vizier catalog, completed with some stars and star names.
V/53A Catalogue of the Brightest Stars (Ochsenbein+ 1988)
This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France
Le catalogue des etoiles les plus brillantes Catalogue of the brightest stars
Ochsenbein F., Halbwachs J.L. =1987BICDS..32...83O
Ochsenbein F., Acker A., Legrand E., Poncelet J.M., Thuet-Fleck E.

AlgorithmsFrom the reference book Astronomical Algorithms by Jean Meeus

Planets : VSOP87D theoryTables extracted from and adapted to Objective-C.

Bretagnon P., Francou G., : 1988, Astron. Astrophys., 202, 309.
Pierre Bretagnon, Gerard Francou Bureau des Longitudes
77, Avenue Denfert-Rochereau F75014, Paris, France

Moon : ELP2000 theory

The lunar ephemeris ELP2000 M. Chapront-Touze and J. Chapront
Service de Mecanique Celeste du Bureau des Longitudes
77, Avenue Denfert-Rochereau F75014, Paris, France

Sky Maps

Free maps from the IAU site :

DeltaT value

What’s New

Version 3.7

Bugs correction

Ratings and Reviews

5.0 out of 5
3 Ratings

3 Ratings

Bud Conroy ,

Excellent app, great service

I use this app every day as a professional navigator. Very good for quick azimuths. iOS update created some color problems. I emailed them, and the problems are fixed with a new version very quickly.

crowding_sail ,

Cool app

I've been impressed with this app since I figured out how to use it. Really all I'm doing with it is using it as a calculator for sights I've taken and it's a labor saver. I use a drum sextant and enjoy it. This calculator makes the solution faster to arrive at. That said, I still do it longhand because electronics can, and often will fail. Of course, this is why we still use sextants and windvanes :p


Denis Froschauer
40.5 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French

Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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