Nautical Calculator Pro vs Sextant
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Nautical Calculator Pro
This app provides comprehensive tools for marine navigation, including real-time ship movement, route planning, and advanced calculations for sailing and maneuvering. It also offers learning resources on maritime regulations and signaling.
- Real-Time Ship Movement
- Route Planning
- Sailing Calculations (Mercator, Great Circle)
- Collision Avoidance Maneuvers
- Wind and Current Calculations
- Nautical Almanac
- COLREG Rules and Marine Signaling
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The application to assist in solving the most important marine problems. - For Marine Navigation: +Real-Time Ship Movement; +Route Plan; + Mercator Sailing; + Greate Circle Sailing; + Meridional parts; + Plane Sailing; + Traverse Sailing. + Wheel over; + Current and wind sailing; + Allowing for current and wind; + Calculate true wind and apparent wind on a ship running; + Nautical Almanac; + Two Lop Fix; + Three Lop Fix; + Correcting marine sextant altitude of sun and stars; + Probability Distribution Function; + Standard Deviation and Error; + Offline GPS; - For Maneuvering : -Avoid collisions ; -Change of station in cases: + with time specified; + with speed specified; + with course specified; + Course and speed of another ship; + Closest point of approach(CPA); + Ability to reach another ship going faster; + Close or open to another ship in cases : - as quickly as possible; - on a constant bearing; - with time specified; + Maneuver to intercept a target ship going faster; + Maneuver to intercept ahead a target ship; + Close to another ship as close as possible; +Keep watch for a target ship within a range of distances; +Maneuvering with added calculating of turning; +Bearing and distance to another ship in advance; - For Learning : +International regulations for preventing collisions at sea (COLREG) include Rules; Lights signs; Shapes signs and Sounds signs; + Marine signalizations include Flag signaling; Morse signaling by hand; Morse code; + Maritime buoyage system; + Unit Conversion for Maritime; + Glossary of Marine Navigation; +Maritime Theory; +Global Lighthouses System; author Vu Cong The. vucongthe@gmail.com - Các tính toán hàng hải và vận động tàu, bao gồm : +Dịch chuyển của tàu theo thời gian thật; +Lập kế hoạch hành trình; +Hành trình theo hải đồ Mercator; +Hành trình theo cung vòng lớn; +Vĩ độ tiến; +Dự tính vị trí tàu một hướng và nhiều hướng; +Tính và đè độ dạt gió dòng; +Tính toán lượn vòng của tàu; +Tính toán gió thực và gió biểu kiến trên tàu đang hành trình; +Lịch thiên văn hàng hải; +Phương pháp hai đường vị trí. +Hiệu chỉnh độ cao mặt trời và sao đo bằng sextant hàng hải; +Tính hàm phân phối xác suất; +Các tính toán bổ trợ; +Tính sai số chuẩn và độ lệch chuẩn; +Hướng đi, vận tốc của tàu mục tiêu; +Tránh va; +Các thông số ở điểm tiếp cận CPA; +Các thông số trận địa với thời gian hoặc khoảng cách cho trước; + Xác định khả năng tiếp cận tàu mục tiêu có vận tốc lớn hơn; +Thay đổi khoảng cách tới một tàu khác với : - Thời gian ngắn nhất; - Thời gian cho trước. - Phương vị không đổi; +Vận động cắt mũi hoặc lái một tàu mục tiêu có vận tốc lớn hơn; +Vận động cắt mũi một tàu mục tiêu; +Tiếp cận một tàu khác ở cự ly ngắn nhất; +Tính các yếu tố trận địa với thời gian hoặc cự ly cho trước; +Thay đổi trận địa trong các trường hợp: -với thời gian cho trước; -với vận tốc cho trước; -với hướng đi cho trước; +Vận động trong dải khoảng cách; +Tính toán lượn vòng trong vận động; -Tra cứu hàng hải bao gồm : + Qui tắc tránh va quốc tế (COLREG) : Nội dung các điều luật, Tín hiệu đèn, Dấu hiệu, Tín hiệu âm thanh; +Thông hiệu hàng hải : Thông tin cờ hiệu, thông tin cờ tay, mã morse; +Hệ thống phao tiêu hàng hải; +Thuật ngữ Tiếng Anh Hàng hải; +Chuyển đổi đơn vị trong hàng hải; +Lý thuyết hàng hải; +Hệ thống hải đăng toàn cầu; +Hệ thống các cảng container bận rộn nhất; Các giao diện hiển thị hai ngôn ngữ : Tiếng Anh và tiếng Việt Tác giả : Vũ Công Thế. vucongthe@gmail.com
Sextant
This app provides a comprehensive celestial navigation toolkit for sailors and enthusiasts. It allows users to navigate using celestial bodies like the sun, moon, planets, and stars, even when GPS is unavailable. The app guides users through taking sextant readings, performing calculations, and plotting positions on a map.
- Celestial body identification using camera and ephemeris
- Sextant sight reduction with manual correction checks
- Offline celestial navigation
- Noon sight for latitude calculation
- Line of position plotting on a real map
- Polaris one-shot latitude
- Solar Compass for deviation checks
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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. Point the camera at the sky The Sky tab labels every navigational body in view — the sun, the moon, all four navigational planets, and 58 navigational stars — using the magnetic compass and on-device ephemeris. Spot a star, tap its name, and a sight starts with that body identified and the time stamped. 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 Learn celestial navigation as you go Step through your first sight with a guided walk-through. Every screen has inline help, and every correction in the sight reduction — dip, refraction, semi-diameter, parallax — has an explanation a tap away. Check the app against your hand calculations, or let it do all the work. 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.
Screenshots
Verdict
The clearest difference is review sentiment: Nautical Calculator Pro at 100% against Sextant's 0%. Nautical Calculator Pro also leads on iOS requirement (17.0 vs 26.0). Sextant's advantage is ads (none vs shown) and price ($9.99 vs $14.99). On update cadence, in-app purchases, monetization model and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Nautical Calculator Pro costs $14.99 and Sextant $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Nautical Calculator Pro ships an update fortnightly, Sextant every 3 weeks. The most recent releases landed on September 23, 2026 and September 24, 2026 respectively.
| Parameter | Nautical Calculator Pro | Sextant |
|---|---|---|
| Price | $14.99 | $9.99 — better |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 100.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 1 — better | — |
| Update frequency | Fortnightly — better | Every 3 weeks |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 17.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 67 MB | 2 MB |
| Age rating | 4+ | +4 |
| Developer | The Vu Cong | Stolk.cc |
Customer experience
Nautical Calculator Pro
Sextant
In-app purchases
Nautical Calculator Pro
No in-app purchases
Sextant
No in-app purchases
Questions
Is Nautical Calculator Pro free?
Is Sextant free?
Do Nautical Calculator Pro or Sextant have ads?
Which is updated more often, Nautical Calculator Pro or Sextant?
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