Comparison

Sight Calc vs Navily

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

Head to head
About

Sight Calc

This app is a specialized calculator for sight reductions using the Law of Cosines method. It's designed for students learning celestial navigation and requires manual input of LHA, declination, and approximate latitude.

Highlights
  • Law of Cosines sight reduction
  • Manual LHA, declination, and latitude input
  • Input as degrees/minutes or decimal degrees
  • Continuous computation of Hc, Z, and Zn
  • Supports North/South latitude and declination conventions
  • Clear and clear entry functions
  • Convert minutes to decimal degrees
Features
Read full description

Sight Calc is a specialized calculator for calculating sight reductions via the "Law of Cosines" method. It does not use Nautical Almanac data, so you must first compute LHA (Local Hour Angle) and declination, and determine your approximate latitude. It is designed particularly for students learning celestial navigation, such as the Celestial Navigation courses taught by the United States Power Squadrons®. If you are unfamiliar with how to do sight reductions, some good resources are available from the United States Power Squadrons® at www.usps.org. In particular, this calculator is useful in conjunction with Form SR96a, www.usps.org/eddept/n/files/sr96a.pdf Inputs may be entered as two numbers: Degrees - left column Minutes - right column Or enter as decimal degrees (e.g., 44.48833). Sight Calc will prompt you to enter six number in sequence: LHA (degrees) LHA (minutes) Lat (degrees) Lat (minutes) Dec (degrees) Dec (minutes) In v 2.0 you may enter values in any sequence. Hc, Z and Zn are continuously computed and displayed. Be sure to enter North Latitude as a positive number and South Latitude as a NEGATIVE number. Sight Calc will take the absolute value of Latitude in the law of cosines formula, but needs the hemisphere to calculate azimuth (Zn). Similarly, enter Declination as positive if North and negative if South. (Note: this differs from version 1.x of Sight Calc.) If you want to do repeated calculations with some of the same numbers, just enter the changed numbers. To start over fresh at any time, press "C" to clear everything. "CE" key clears the Current Entry. Optionally, use the "o" key to convert minutes to decimal degrees, add that to the degrees field, and clear the minutes field. This has no effect on the calculation. Please report any bugs or suggestions to: sightcalc@nuvocom.com

About

Navily

This app serves as a comprehensive mobile cruising guide for boaters. It offers a vast database of marinas and anchorages, user-generated reviews and photos, and seamless berth booking across Europe. Connect with other users and marinas through in-app chat and receive real-time warnings.

Highlights
  • 35,000+ marinas and anchorages
  • 350,000+ community photos and comments
  • Easy berth booking in 700+ European marinas
  • In-app chat with users and marinas
  • Real-time anchorage warnings
  • Emergency SOS feature
Features
Read full description

With over 1.2 million boaters worldwide, Navily is the all-in-one boating and sailing app to discover safe anchorages, book marinas with ease, and cruise with confidence. Whether you're planning a day trip, a sailing holiday, a coastal cruise, or an offshore adventure, Navily gives you everything you need in one place. Trusted by sailors, cruisers, and recreational boaters around the world, Navily helps you plan routes, discover the best marinas and anchorages, and make every journey easier. Explore more than 35,000 marinas and anchorages backed by 500,000+ trusted reviews and photos from the Navily community and our marina partners. Why choose Navily? - A growing community with over 1.2 million boaters worldwide - 35,000+ marinas and anchorages - 500,000+ reviews and photos - 700+ bookable marinas - Smart route planning and distance calculations - Navily Protection Scores to find the best anchorages - Live chat with nearby boaters - Real-time anchorage alerts - Emergency SOS feature- ask the community for help! Plan smarter boating routes. Spend less time searching and more time sailing. Compare nearby marinas and anchorages, calculate distances, filter results to match your preferences, discover the best locations to anchor with Navily Weather Protection Scores, and build routes with automatic itinerary planning. Whether you're cruising the Mediterranean or exploring the Caribbean, Navily helps you make better decisions before you leave the dock Sail with confidence. - Access over 500,000 community reviews and photos to find the perfect stop, including: - Depth and seabed information - Wind and swell protection - Marina facilities and services - Local tips from experienced boaters - Real photos from fellow sailors - Every review is automatically translated, allowing you to benefit from the knowledge of our international boating community. - Stay connected through community chat, receive real-time anchorage alerts, and access essential services both ashore and at sea. When you're off the grid, Offline Mode keeps important information available whenever you need it. Unlock even more with Navily Premium. Upgrade to Navily Premium and enjoy: - View a 72-hour anchorage protection score before you drop anchor - Filters the map to your preferences and boat requirements - AI-powered summaries of all community comments - Offline-mode, no internet needed. Navily is also available in French, Spanish, German and Italian. Want to help us improve Navily? Find us on Facebook, Twitter or Instagram and share your stories with us, we are passionate about what we do! Facebook: https://www.facebook.com/navilyApp Twitter: https://twitter.com/navilyapp Instagram: http://instagram.com/navilyapp Blog : http://blog.navily.com/ Website : https://www.navily.com/ Privacy policy : https://www.navily.com/privacy Terms of Use : https://www.navily.com/cgu

Screenshots

Sight Calc4 screens
Navily4 screens

Verdict

The call

The clearest difference is price: Navily at Free against Sight Calc's $1.99. Navily also leads on update cadence (every 2 weeks vs every 11 months) and ratings volume (813 vs 7). Sight Calc's advantage is in-app purchases (none vs 4) and rating (5.0 vs 4.8). On ads, device support and iOS requirement 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

Navily is free to download; Sight Calc costs $1.99 up front. Navily sells 4 in-app purchases, starting at $9.49 per year. Sight Calc asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Sight Calc holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Navily has 813 ratings behind it against 7, so its average is the more settled of the two. Written reviews complicate that: 82% of Sight Calc's written reviews are positive against 93% of Navily's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Sight Calc ships an update every 11 months, Navily every 2 weeks. The most recent releases landed on September 10, 2026 and September 27, 2026 respectively.

Scorecard8 real differences · 3 level
Sight Calc versus Navily: the parameters behind the verdict, then further details
ParameterSight CalcNavily
Price$1.99Free — better
Rating5.0 (7 ratings) — better4.8 (813 ratings)
Positive reviews82.4% of reviews93.4% of reviews — better
Number of ratings7813 — better
Update frequencyEvery 11 monthsEvery 2 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
Best chart rank—#188 — better
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.016.0
Further details — not scored
Size1 MB235 MB
Age rating4+4+
DeveloperNUVOCOM INCORPORATEDThe Navigation Family

Customer experience

Sight Calc

All ratings7 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews17 reviews
Positive82.4%
Neutral0.0%
Negative17.6%

Navily

All ratings813 ratings
Positive96.2%
Neutral1.6%
Negative2.2%
Written reviews229 reviews
Positive93.4%
Neutral2.2%
Negative4.4%

Bugs and requests

Sight Calc

Not enough reviews yet to summarise bugs or requests.

Navily

Reported bugs

3 issues
  • Booking cancellations not working
  • Spinning icon issue with past bookings
  • Difficulty accessing messages from map view

Requested features

5 requests
  • Offline map downloads
  • Improved route planning tools
  • Live chat with other users
  • Customizable notifications
  • Better integration with navigation apps

In-app purchases

None

Sight Calc

No in-app purchases

4 purchases

Navily

Subscriptions3
  • Navily Premium$9.491 Year
  • Navily Premium$18.491 Year
  • Navily Premium$24.991 Year
One-time1
  • Navily Premium 30 days$17.99

Questions

Is Sight Calc free?
Sight Calc costs $1.99, with no in-app purchases.
Is Navily free?
Navily is free to download, with in-app purchases available.
Which has better reviews, Sight Calc or Navily?
Sight Calc is rated higher. Sight Calc averages 5.0 out of 5 from 7 ratings, while Navily averages 4.8 from 813 ratings.
Do Sight Calc or Navily have ads?
Neither Sight Calc nor Navily shows ads.
Which is updated more often, Sight Calc or Navily?
Sight Calc ships an update every 11 months, and Navily every 2 weeks. Most recently, Sight Calc was updated on September 10, 2026 and Navily on September 27, 2026.

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