SailTimer™ vs qtVlm
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SailTimer™
Visualize wind and wave conditions before you head out on the water with this marine weather app. It uses crowdsourced data for more accurate, real-time forecasts than traditional satellite imagery. Track your GPS, create waypoints, and access offline charts for any boat type.
- Crowdsourced wind and wave map animation
- Route viewing with aerial photos and land maps
- Waypoint creation and GPS track saving
- Offline map and chart usage
- Follow-Me GPS tracking
- Optimal tacking distance calculation for sailboats
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For all types of boats. Beautiful marine weather animations: • Crowdsourced wind maps for the most accuracy and highest resolution. • Marine weather forecasts from Weathernews Inc. (WNI) with maps of precipitation, visibility, air & sea temperature, wind, waves/swell & ocean currents. • AI models of ocean currents and marine weather from Amphitrite. There are lots of weather services and apps, but they all use the same satellite weather forecast. Low resolution, low accuracy, and only updated 4 times per day. Weather satellites are 500 to 22,000 miles up in space. Crowdsourcing is changing marine weather. Why rely on satellite imaging, when you can use actual measurements from other boaters? In coastal areas, we archive these to map wind flow for more accuracy. Crowdsourced weather maps like these have never been possible before. A wind sensor measures local wind around your boat, but now you can also know the wind and sea state up ahead or around the next point. FEATURES FOR ALL TYPES OF BOATS: • View your route with free aerial photos and land maps worldwide. If you have the Navionics Boating app, you can import worldwide Navionics charts here with a yearly subscription. • The weather map animations each have low-cost monthly/yearly subscriptions with a free 7-day trial. • Hourly weather tables for crowdsourced wind and WeatherNews Inc. (WNI) weather maps. Tap on a certain hour to move the weather animation to that time. • Create and rename waypoints by tapping or importing a list. Save, import or email your GPS track. • All maps and charts in the app can be used offline. • The white crosshair icon in the top left is the “Follow-Me” button. If tapped, it turns blue and keeps your location in the center of the screen as you move. Unselect when not moving to look around the map. • Your device will not go to sleep when the app is open, to allow you to continue to monitor your progress on the chart. You can also continue to track your movement with the app running in the background or when the device is asleep (unless you hard-quit). (Note: Continued use of GPS running in the background can dramatically decrease battery life. This app may use your location even when it isn’t open, which can decrease device battery life.) FOR SAILBOATS: Whether cruising or racing, it is important to be able to determine the best heading on all points of sail. GPS chartplotters do not calculate tacking distances. But if they do not know the distance you will travel, how can they calculate your correct ETA? This is the only product that calculates your optimal tacks using your tacking distance and polar plots. Details at www.SailTimerApp.com. The SailTimer app gives you a quick and easy display of your optimal tacks and TTD® (Tacking Time to Destination). • Use our wireless Wind Instrument or wired Ultrasonic (www.SailTimer.co) to see wind direction, angle & speed. Enter a waypoint and your optimal tacks will update automatically as the wind changes. • Bring in wind data from any other wind sensor on wifi from NMEA 2000 or 0183, using our low-cost Air Link™ (https://wi-rb.com/airlink). • Custom polar plots: When using a wind sensor, the app can learn your sailboat's unique speed profile on all points of sail, for the most accurate tacking results. • Switch the display to the port or starboard tack to avoid obstructions, or let the app automatically display the tack nearest to your current heading. • Audio Navigation: when using the wireless Wind Instrument, optionally hear wind conditions or boat speed when they change by more than a set amount. • Convert from Apparent to True wind direction, angle & speed. See our channel on Tiktok and YouTube for more background.
qtVlm
This navigation software is designed for sailing boats, offering a free version with basic GRIB viewing and an optional full version with advanced weather routing, chart modules, and communication features. It supports various chart formats and NMEA data sources, with a simulation mode for learning.
- GRIB viewer with advanced functions
- Weather routing and route modules
- Support for Raster, Vector, and MBTiles charts
- Harmonic file support for tides and currents
- AIS and Iridium GO! communication
- Anchor Alarm module
- Simulation Mode for learning
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qtVlm is a navigation software for Sailing Boats. The application has a free version with basic features and a full version available through in-app purchase. The free version of qtVlm is a full grib viewer displaying all types of gribs and providing many advanced grib functions. It supports basics charts and some simple instruments. It includes also an Anchor Alarm module, a viewer for shapefiles, for instance those coming from SHOM, and can be configured to receive boat position either from internal GPS or from an external NMEA source connected through tcp, udp or gpsd. The full version adds many functions and features: - Weather routing and route modules, - A complete set of navigation Instruments, - Charts modules for Raster charts, Vector charts (S57, S63 and CM93) and mbtiles, - Support for Harmonic files (tides and currents), - Iridium GO! communication - AIS, - Start line mode, - Access to Great Circle gribs, qtVlm can also be used in Simulation Mode, which allows you to simulate a navigation through our server. This is the best way to learn using qtVlm. Once activated the full version will be available on all your iOS devices.
Screenshots
Verdict
The clearest difference is review sentiment: qtVlm at 79% against SailTimer™'s 37%. qtVlm also leads on update cadence (weekly vs every 2 months). On price, ads, in-app purchases and monetization model 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. SailTimer™ sells 12 in-app purchases, starting at $2.99 per month and qtVlm sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
SailTimer™ ships an update every 2 months, qtVlm weekly. The most recent releases landed on October 16, 2026 and October 14, 2026 respectively.
| Parameter | SailTimer™ | qtVlm |
|---|---|---|
| Price | Free | Free |
| Rating | — | 3.5 (8 ratings) — better |
| Positive reviews | 37.0% of reviews | 79.2% of reviews — better |
| Number of ratings | — | 8 — better |
| Update frequency | Every 2 months | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 126 MB | 100 MB |
| Age rating | 4+ | 4+ |
| Developer | SailTimer Inc. | Meltemus SAS |
Customer experience
SailTimer™
qtVlm
In-app purchases
SailTimer™
- WNI Marine Weather Map7 Days trial$2.991 Month
- Wind Animation7 Days trial$2.991 Month
- Navionics Charts$10.991 Year
- ActiveCaptainFree
- Polar Plot LearningFree
- Import NMEA data$0.99
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- SailTimer Pro Bundle$7.99
- USA Atlantic Coast$15.99
- USA Pacific Coast$15.99
- USA Great Lakes$15.99
- USA Gulf Coast$15.99
- Cuba, Bahamas, Puerto Rico and US Virgin Islands$15.99
qtVlm
- Full version$49.99









