Dsky vs C
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Dsky
Experience the Apollo Guidance Computer DSKY interface on your iPad. This photo-realistic simulator lets you input commands like Apollo astronauts to navigate, using your device's GPS and accelerometers for real-world data.
- Photo-realistic DSKY interface simulation
- Uses iPad GPS for latitude, longitude, altitude
- Utilizes iPad accelerometers for attitude
- Subset of original DSKY verbs and nouns
- Configurable units (meters, nautical miles, statute miles)
- Includes help page and usage instructions
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Description Tap on the 'i' icon lower right for help on using Dsky. Dsky is the Apollo Guidance Computer DSKY simulator for iPad. Dsky simulates the look and feel of the original Apollo DSKY keyboard and user interface used by the Apollo astronauts to navigate to the moon and back in the 1960’s and 70’s. Dsky is a photo-realistic simulation, based on actual photographs of original Apollo DSKY hardware, realistically animated for the iPad to be as close as possible to the real thing. The Apollo Guidance Computer (AGC) and DSKY user interface were installed in every Apollo Command Module (CM) and Lunar Excursion Module (LEM) that flew in the Apollo program. They were used to navigate and control the spacecraft in all phases of flight. The AGC and DSKY were designed and programmed by MIT for NASA, and although they were among the most advanced electronics of their time, the DSKY user interface was necessarily limited and simple. Now you can use this exact same interface to do your own navigation! Its harder than using a Tom-Tom, but you know, this actually is rocket science. And its free! Although you can’t use Dsky to maneouvre your LEM or land on the moon, you can use it for some real-world down-to-earth applications: Current GPS Latitude, Longitude and Altitude Current attitude using the iPad acccelerometers. Distance-to-go, time and velocity, using the iPad internal GPS. A subset of the original DSKY verbs and nouns is faithfully implemented, allowing you to program and use the Dsky just like the Apollo astronauts did. Unlike the original DSKY, you can configure Dsky to use your own choice of units: Meters, Nautical Miles or Statute Miles. See the iPad Settings page. A comprehensive help page and usage instructions is included (look for the little ‘i’ at the bottom right of Dsky).
C
Access up-to-date nautical charts for global exploration and planning. Save points of interest and routes, record tracks, and view marine weather. Upgrade for offline maps, GPS, and advanced features like shaded relief and AIS.
- Free chart viewer
- Autorouting
- Personal waypoints
- Track recording
- Marine weather forecasts
- Offline map downloads
- High-resolution bathymetry
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The C-MAP® App is the perfect companion for recreational boaters and water-lovers. Available on Mobile, Tablet or PC, you’ll always be able to access the most up to date C-MAP charts, wherever in the world you are. With full features, allowing you to explore, plan and save Points of Interest and Routes from wherever you are, the C-MAP App is the perfect aid to navigation for savvy boaters. The C-MAP App Includes: - FREE Chart Viewer - Autorouting™ – find the best route to your favourite places - Personal Waypoints - Track Recording - Thousands of pre-loaded Points of Interest - Marine Weather Forecast - Weather Along the Route - Weather Overlay - Chart Personalisation - Import & Export GPX Files – share your Routes, Tracks or Waypoints with friends - Measure Distance Tool Upgrade to Premium to unlock additional features, including: - Full GPS Functionality - Offline Map Downloads - REVEAL Shaded Relief - High-Resolution Bathymetry - Custom Depth Shading - AIS & C-MAP Traffic Try before you buy… Experience C-MAP App Premium for yourself, with a free 14-day trial (3-day trial in Denmark and Sweden). The C-MAP App updates on a continual basis, ensuring the latest, most up-to-date maps are always at your fingertips. Payment will be charged to iTunes Account at confirmation of purchase. Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal. Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase. Links to Your Privacy Policy and Terms of Use. Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable Privacy Policy: https://www.brunswick.com/dsar Terms of Service https://appchart.c-map.com/tos.html
Screenshots
Verdict
The clearest difference is in-app purchases: Dsky at none against C's 11. Dsky also leads on review sentiment (86% vs 51%) and iOS requirement (8.0 vs 15.1). C's advantage is update cadence (every 6 weeks vs every 32 months) and ratings volume (2.3K vs 11). On price, rating 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
Both are free to download. C sells 10 in-app purchases, starting at $1.99 per month. Dsky asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.6 for Dsky against 4.5 for C. That said, the two scores are not equally well evidenced: C has 2.3K ratings behind it against 11, so its average is the more settled of the two. Written reviews are what separate them: 86% of Dsky's written reviews are positive against 51% of C's.
Dsky ships an update every 32 months, C every 6 weeks. The most recent releases landed on September 14, 2026 and October 2, 2026 respectively.
| Parameter | Dsky | C |
|---|---|---|
| Price | Free | Free |
| Rating | 4.6 (11 ratings) — better | 4.5 (2.3K ratings) |
| Positive reviews | 85.7% of reviews — better | 51.0% of reviews |
| Number of ratings | 11 | 2.3K — better |
| Update frequency | Every 32 months | Every 6 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Best chart rank | — | #100 — better |
| Devices | iPad | iPhone, iPad, iPod — better |
| Requires iOS | 8.0 — better | 15.1 |
| Further details — not scored | ||
| Size | 9 MB | 169 MB |
| Age rating | 4+ | 4+ |
| Developer | AirSpayce | Navico Norway AS |
Customer experience
Dsky
C
Bugs and requests
Dsky
Not enough reviews yet to summarise bugs or requests.
C
Reported bugs
4 issues- App crashes when trying to save tracks or routes
- Offline maps fail to download or disappear
- Depth/contour data inaccurate or not displaying properly
- Login and authentication issues preventing access
Requested features
4 requests- Add mast height/clearance feature
- Improve AIS integration and functionality
- Allow more customization of map views and data
- Provide better customer support and communication
In-app purchases
Dsky
No in-app purchases
C
- Embark Advanced Weather$1.991 Month
- Embark Offline Maps USA$2.491 Month
- Annual Subscription14 Days trial$14.991 Year
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- Annual subscription14 Days trial$14.991 Year
- Region14 Days trial2 variants$18.991 Year
- North America14 Days trial$23.491 Year
- Maps Lakes South East USA14 Days trial$25.991 Year
- Annual Subscription14 Days trial$29.991 Year
- Caribbean14 Days trial$32.991 Year
- Maps USA East Coast & Bahamas14 Days trial$39.991 Year









