Sextant — Celestial Nav
Learn to navigate by the stars
$5.99 · Designed for iPad. Not verified for macOS.
A complete celestial navigation toolkit for sailors, students, and the curious.
When the GPS quits, the sun, moon, planets, and stars still work. Sextant takes you all the way from a single sextant reading to a line of position on a map — with every correction shown, so you can check the math by hand if you want to.
Sight with your camera, or a real sextant
The camera flow uses gravity-based altitude with a roll lockout so a tilted phone can't slip a bad shot through. Multi-shot mode takes a series and saves the trimmed mean. Or just type your altitude from a brass sextant and let the app do the reduction.
Every body you'll ever shoot
Sun, moon, all four navigational planets — Venus, Mars, Jupiter, Saturn — and all 58 standard navigational stars. Positions computed from astronomical models (Meeus, VSOP87, JPL Keplerian elements), not stale tables. Works fully offline.
Noon Sight in one tap
Take the sun's altitude at meridian passage; the app gives you latitude. It also predicts the exact UTC of local apparent noon so you know when to look.
Plot your fix
Every sight draws a line of position on a real map. Take more than one, apply dead reckoning between them, watch your running fix come together — exactly like the paper-chart workflow.
Tools sailors actually use
- Polaris one-shot latitude
- Solar Compass — true bearing of the sun, for compass deviation checks
- Starfinder — what's above the horizon right now
- Reduction tables (dip, refraction, semi-diameter)
- DMS / decimal converter
Built-in tutorial
Step through your first sight with a guided walk-through. Every correction has an explanation tap away.
Share your work
Export sight records as CSV or as a printable PDF work-form in the classic HO 229 layout.
No subscription. No ads. No internet. One purchase, everything included.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Point your phone at the sky.
The new Sky tab labels every navigational body in view — the sun, moon, all four navigational planets, and 58 navigational stars. Magnetic compass plus on-device ephemeris. No internet required.
Tap a label to start a sight on that body with the time already stamped.
If your compass is noisy, Sky tells you and shows the figure-8 motion to recalibrate.
The developer, Stolk.cc, 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.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Creative4Vision
- Size
- 2.4 MB
- Category
- Navigation
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - iPad
Requires iPadOS 26.0 or later. - Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Driftwatch

