# SailTimer API™ > Bluetooth wind instrument data relay for sailing and charting applications. (iPhone/iPad app by SailTimer Inc..) - Source: https://appshunter.io/ios/app/sailtimer-api/id959558893 (this page in markdown: same URL + `.md`) - Developer: [SailTimer Inc.](https://appshunter.io/developer/326309854) - Category: Weather, Navigation - Price: Free - Rating: 3.00/5 from 2 App Store ratings · 4 written reviews indexed - Age rating: 4+ - Requires: iOS 9.0 · 11 MB - Languages: American English - Released: 2015-08-10 - Data updated: 2026-06-10 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/sailtimer-api/id959558893/reviews.md ## What is SailTimer API™? The SailTimer API™ handles the Bluetooth 4 LE connection to the SailTimer Wind Instrument™. You can let the API run in the background. It hands off the wind data to other sailing, racing or chartplotting apps. Logging in will also let you access new sailing innovations as they become available, like the Share button that gives you the option to crowd-source your wind data and view real-time wind maps to plan your tacking routes. You can Register the first time in the API or at www.SailTimerMaps.com. Then you can simply log in to the API, and you won’t have to log in again for a long time. (Perhaps only if you get a new version or delete the app and then re-install it.) The API is a toolkit that receives wireless wind data from the SailTimer Wind Instrument™ (www.SailTimerWind.com), and reformats it to make it easy for other apps to display. We receive the Bluetooth 4 (Low Energy) transmissions in the API, so that other apps receiving this data would not have to each learn and build this code themselves. The API also converts wind direction from magnetic to true north, and converts the wind data to NMEA 0183 format. You don’t need to understand the NMEA 0183 data, but it starts streaming in green letters so that you can see when the connection is made. This is the data that other apps use to display the wind speed and direction on a wind gauge, graph or tacking angles on a chartplotter. The MWD sentence is the standard sentence in marine electronics for wind direction. True (not apparent) wind direction and wind speed is shown. You can add an identifier like your boat name to your Wind Instrument by clicking on the “i” on the line where it is listed. This is handy to do before multiple Wind Instruments start showing up in your marina, to identify yours. No-one else can see this, but it ensures that you are trying to connect to your own Wind Instrument. Once yours is connected, any others will not be displayed. There is also a Smoothing button on this panel, if the wind direction is jumping around a lot and you want to average it. Also under the “i” is the Advanced button, for Compass Quadrant Fine-Tuning. Although your Wind Instrument was pre-calibrated at the factory, if you want to fine-tune the precise degrees for North, East, South and West where the Wind Instrument is mounted on your boat, there are innovative fine-tuning adjustments for wind direction under the “i” on the line of you The API is designed to try to reconnect automatically if the Bluetooth 4 (Low Energy) signal is lost, or the next time you come back to the boat. But to connect the first time or if you need to re-connect, just press “Scan for Devices”, and then tap on the line for your Wind Instrument when it is found. There is a Disconnect icon in the upper right corner that allows you to disconnect the Bluetooth and Location Services. That is handy when leaving the boat, or also if you want to save power in the iOS device and in the Wind Instrument when not in use. The Wind Instrument uses about 44% less power when Bluetooth is not connected. Similarly, your iPad/iPhone uses less power when the GPS (Location Services) and Bluetooth are shut off, either in Settings or with the Disconnect icon. 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. *If you are getting the app and like this wireless technology, please help out other sailors by letting them know, with a quick rating on this version while you’re here. ## Key features - Bluetooth 4 LE connection - Background data streaming - Wind data reformatting - Magnetic to true north conversion - NMEA 0183 data output - Automatic reconnection - Compass quadrant fine-tuning ## Recent user reviews (4 of 4) All indexed reviews: https://appshunter.io/ios/app/sailtimer-api/id959558893/reviews.md ### 1/5 — Still Flaky... *2020-12-09, version 1.3.6* I purchased the SailTimer wind instrument and have so far been very disappointed. After a long wait, my wind sensor arrived heavily scratched and with a battery that will only reach half a charge. The SailTimer API app eventually connected to the device but drops off frequently. Tech support is only through email and my technical questions emails have gone unanswered. Return policy is essentially a joke. Lots of promise on the design side but the company appears to lack the organization to make all the parts and pieces actually work. 2020 Update. I tried using the SailTimer system for two sailing seasons in Maine. The app was generally pretty good, nothing cutting edge, but functional. The system hardware, the wireless wind sensor, was abysmal and customer service was even worse. The standard company response is to deny any fault and blame the customer for everything. If I had taken the time for more research I would have found my bad experiences were not unique. I would avoid this company like the plague. **Developer response:** We stand behind our products, and have also had dialogue with you via your posts in other places. Contacting our developers and expert sailors at Technical Support is the best way to get help. (As later determined, your email form was never sent in, but we do provide prompt 24/7 support to sailors worldwide.) Although you did not update your original comment above, we trust that things are better now now, and appreciate this explanation you sent in on August 7 2019: “The wind instrument is atop my mast and being used.  Your software is good and when the instrument is connected the overall system is very useful.” ### 1/5 — Unusable *2017-02-18, version 1.2.9* Cannot login after registering on an iPad or iPhone 7 iOS 10.2. Is completely unusable without login. ### 1/5 — Registration function broken *2017-01-04, version 1.2.7* The registration function of the API app appears to be fatally flawed. After agreeing to the terms and conditions a pop up asks to "pick a color". There is no place to specify a color or select from a drop down list. You are just returned to the registration field entry page which puts the user in and endless loop. This renders the app useless. Using an iPhone 7 Plus and iOS 10.2 ### 2/5 — Some issues using iOS 9 *2016-01-01, version 1.2* I've got an iPhone 5S iOS 9. The api screen for log-in doesn't quite fit. When logged in, and the WindInstrument found and identified, you can just barely see the top of the signal strength bars but the clickable area of the instrument button is hidden so you can't select it. Works fine with my iPad Air 2. Hope you will check this issue out. Simeon ## Frequently asked questions about SailTimer API™ ### What is the SailTimer API™ used for? The SailTimer API™ connects to the SailTimer Wind Instrument™ via Bluetooth 4 LE to receive and reformat wind data. This data is then handed off to other sailing, racing, or chartplotting applications for display. ### Does the SailTimer API™ work with any wind instrument? No, the SailTimer API™ is specifically designed to work with the SailTimer Wind Instrument™. It receives wireless wind data transmissions from this particular device. ### Can I see wind data from other users with the SailTimer API™? Yes, by logging in, you can access innovations like the Share button, which allows you to crowd-source your wind data and view real-time wind maps to plan your tacking routes. ### How does the SailTimer API™ handle wind direction? The API converts wind direction from magnetic north to true north. It also reformats the wind data into NMEA 0183 format, which is a standard sentence (MWD) used in marine electronics for wind direction and speed. ### What are the advanced features in the SailTimer API™? Under the 'i' menu, you can find a Smoothing button to average fluctuating wind direction readings. There is also an Advanced button for Compass Quadrant Fine-Tuning, allowing precise adjustments for North, East, South, and West based on the instrument's mounting on your boat. ### How often is the SailTimer API™ updated? The latest version is 1.3.7, which was last updated on January 18, 2021. Update frequency can vary, but this indicates it receives periodic maintenance. ### What devices is the SailTimer API™ compatible with? The SailTimer API™ is available for iPhone, iPad, and iPod. It requires Bluetooth 4 LE for connection to the wind instrument. ### What is the rating for the SailTimer API™? The app has a rating of 3.0 stars based on 2 ratings. This suggests a mixed user reception, possibly due to specific use cases or connectivity issues. ## Version history (last 5 releases) ### 1.3.7 — 2021-01-18 Updated NOAA geomagnetic model for wind direction based on Magnetic North or True North. ### 1.3.6 — 2019-05-14 • Layout improvements on iPhone. ### 1.3.5 — 2018-06-12 • Adjustment for using the same login on an iPad and an iPhone at different times with the wireless Wind Instrument. • Interface adjustment for iPhone X screen. ### 1.3.4 — 2018-06-01 • Adjustment for using the same login on an iPad and an iPhone at different times with the wireless Wind Instrument. ### 1.3.3 — 2017-07-03 • Interface adjustment for iPhone and iPod Touch. • Updated for the 5th-generation SailTimer Wind Instrument™ (SailTimerWind.com). • Can now display air temperature from the Wind Instrument, or share on SailTimerMaps.com if you want to view the temperature online. • Additional security and encryption procedures to protect your Bluetooth data. • Polar plot learning is now included in the API, so that you can export your optimal tacks and TTD® (Tacking Time to Destination) to other apps (and soon also for viewing on the free worldwide marine charts at SailTimerMaps.com). Have questions? There are How-To-Use pages and FAQs at www.SailTimerWind.com. Since we cannot reply to comments in the App Store, if you have a question or feedback please email info@SailTimerInc.com. 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User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*