Comparison

Binnacle vs Compass Observation App

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Binnacle

This navigation app provides tools for maritime professionals and sailing enthusiasts. It offers features like true wind calculation, celestial navigation, ETA estimation, logbook management, and port search. Stay informed with real-time NavArea warnings for safer voyages.

Highlights
  • True Wind Calculation
  • Celestial Navigation Tools
  • ETA Estimation
  • LogBook Management
  • UNLOCODE Search
  • NavArea Warnings
Features
Read full description

Binnacle is a set of bridge instruments for merchant marine deck officers. Thirteen tools, most of them working with no signal, and none of them pretending to be more certain than it is. ON WATCH • Navigational warnings, plotted. NAVAREA and the coastal services drawn on a chart where they actually are, instead of read as a wall of text at three in the morning. Set a radius from your position and follow only the services that concern the passage. • Weather for a position and a time you choose — wind in forces, the barometric tendency, fog risk. Forecast data from MET Norway. • True wind from course, speed and apparent wind. • Manoeuvring board — CPA and TCPA for two to five contacts at once, and one alteration that clears all of them. POSITION AND CHECKS • Compass error by amplitude or azimuth, worked against celestial data for the moment you observed. • Celestial fix — reduce two or three sights and see the cocked hat plotted, with its residuals, not just a number. • ETA and passage timing in UTC, with the arithmetic shown. • Heel, trim and roll period from the phone's own sensors, with GM estimated from the roll period. RECORDS AND REFERENCE • Log book for bridge events, kept for the whole contract and handed over as a PDF. • 17,998 ports by UN/LOCODE, and 11,728 port facilities with their GISIS codes, searchable by name or code — the reference is bundled, so it works alongside. • Manoeuvring miles — passage legs with sea and manoeuvring totals kept apart. • Unit converter for the units a bridge actually uses: knots, cables, fathoms, hectopascals, tonnes and the rest. WHAT IT WILL NOT DO It is an aid, not an authority. It does not replace corrected charts, official publications, the ship's procedures or the officer's judgement. Every screen states its own limits rather than hiding them, and every export says on its face what it is. WHAT STAYS FREE True wind, ETA, compass error, the manoeuvring board, heel and trim, weather and the unit converter are free, with no limit and no trial. The log book keeps ten entries free. Celestial reduces one sight free. Port search and the match count are free. ONE PURCHASE, NOT A SUBSCRIPTION • Navigational warnings — NAVAREA and the coastal services, with the chart and the radius • The facility's own record in Port Facilities • Fixes from two or three lines of position, and the plot • PDF export, on every screen including the free ones One payment of $5.99 unlocks all of it, on every device signed in to your Apple Account. There is no subscription, nothing renews, and there is nothing to cancel. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy and Terms are also in the app, under More.

About

Compass Observation App

This navigation app provides tools for deck officers, yachtsmen, and students to check compasses and perform celestial navigation calculations. It offers offline functionality, no account required, and no data collection for a private user experience.

Highlights
  • Phone compass calibration
  • Gyro and standard compass error calculation
  • Sight reduction and fix plotting
  • Meridian passage countdown
  • Latitude by Polaris calculation
  • Coastal navigation tools
  • AR Sky for celestial body identification
Features
Read full description

The compass check and celestial navigation toolkit for deck officers, yachtsmen and navigation students. Everything is calculated on your phone, offline, with no account, no ads and no data collection. PHONE COMPASS • Your heading, magnetic or true, with the Sun, the Moon and your chosen body marked on the dial • Find your phone's own compass error by aligning it to the Sun or the Moon; AR Sky uses the same correction COMPASS & GYRO ERROR • Gyro and standard compass error from any body's true bearing, with variation (World Magnetic Model) and deviation worked out for you • SOLAS gyro-error limit check for your latitude • Amplitude worksheet: compass error at sunrise or sunset, with the exact bearing for the Sun's centre on the visible horizon (dip, refraction and parallax applied) as well as the classic formula • Deviation cards with a fitted deviation curve and a PDF report SIGHT REDUCTION & FIX • Enter your sextant altitude in degrees and minutes as the sextant reads it • Index error, dip, refraction (with air temperature and pressure), semi-diameter and parallax, including the Moon's augmentation • Intercept and azimuth (Marcq St-Hilaire), drawn on a plotting sheet • Show calculation: every step written out with its formula, then with your sight's numbers • Fix from two or more saved sights by least squares, including running fixes with course and speed, plotted with every line of position • Meridian Passage: the time of noon for your DR, course and speed, and your latitude from the noon sight, every step shown; a morning sun line run up to noon gives the noon position • A countdown to meridian passage on your chronometer, in UTC or ship's time: it ticks faster over the last minute and sounds a tone at the passage • Latitude by Polaris at any time of the night, worked out exactly for the moment of the sight (northern hemisphere) • Ship's time: set the zone your ship keeps, and times are shown on the ship's clock • Twilight Stars: the best 3 to 5 stars for a fix at the next morning or evening twilight, spread round the horizon, with the altitude to preset on the sextant and the bearing to face; tap one to find it in AR Sky COASTAL NAVIGATION • Distance off a lighthouse, cliff or charted peak by its vertical sextant angle, to its waterline or to the sea horizon, with the tide below high water springs, your height of eye, the earth's curve and refraction (Bowditch's tables) • The vertical danger angle: the most the sextant may read to stay outside a clearing distance • Where a light rises or dips over the horizon: its distance from its height and yours, for a fix with one bearing SKY & EPHEMERIS • Sun, Moon, planets and the 57 navigational stars plus Polaris, computed to almanac accuracy (VSOP87 and Meeus algorithms, with nutation, aberration, refraction and ΔT) • Rise, set, transit and twilight times • Star Dome: the whole sky at a glance, with GoTo to any body • AR Sky: point your camera at the sky to see stars, planets, the Sun and Moon, all 88 constellations, classic Hevelius constellation art and the Milky Way. Search any star, planet or constellation and the app points you to it. AT SEA • Logbook of compass checks, sights and fixes, with CSV export • Dark, light and red night-vision themes that protect your night vision on the bridge Star data: HYG Database (CC BY-SA 4.0). Moon and Milky Way imagery: NASA Scientific Visualization Studio. Constellation art: Johannes Hevelius (1690), public domain. Compass Observation App is a training and cross-checking aid. It is not a substitute for official nautical publications or the ship's primary means of navigation; always verify with approved sources.

Screenshots

Binnacle4 screens
Compass Observation App4 screens

Verdict

The call

The clearest difference is update cadence: Compass Observation App at every 3 days against Binnacle's every 2 weeks. On price, rating, ratings volume and ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Binnacle against 5.0 for Compass Observation App. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

UpkeepUpdate frequency

Binnacle ships an update every 2 weeks, Compass Observation App every 3 days. The most recent releases landed on October 30, 2026 and November 6, 2026 respectively.

Scorecard1 real difference · 9 level
Binnacle versus Compass Observation App: the parameters behind the verdict, then further details
ParameterBinnacleCompass Observation App
PriceFreeFree
Rating5.0 (1 ratings)5.0 (1 ratings)
Positive reviews100.0% of reviews—
Number of ratings11
Update frequencyEvery 2 weeksEvery 3 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhoneiPhone, iPod — better
Requires iOS16.015.0 — better
Further details — not scored
Size32 MB36 MB
Age rating4+4+
DeveloperDanylo BudylkinBurak Yesilirmak

In-app purchases

None

Binnacle

No in-app purchases

None

Compass Observation App

No in-app purchases

Questions

Is Binnacle free?
Binnacle is free to download, with no in-app purchases.
Is Compass Observation App free?
Compass Observation App is free to download, with no in-app purchases.
Which has better reviews, Binnacle or Compass Observation App?
Binnacle and Compass Observation App are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.
Do Binnacle or Compass Observation App have ads?
Neither Binnacle nor Compass Observation App shows ads.
Which is updated more often, Binnacle or Compass Observation App?
Binnacle ships an update every 2 weeks, and Compass Observation App every 3 days. Most recently, Binnacle was updated on October 30, 2026 and Compass Observation App on November 6, 2026.

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